Comments: Bought this string for my brother who is a rec player who loves to smash the ball and has used thicker strings in the past to break them less often. He wanted a string to place string savers on and leave in his racquet for as long as possible without it breaking. I bought a reel of this thinking it would be better than poly for retaining long term playability and was able to experiment with this string on my own racquets. The comfort and muted feel is wonderful but spin production is poor. Strung at 62 pounds in my Wilson Pro Staff 85, it was very low powered with a wonderfully comfortable and solid feel (compared to a full bed of gosen sheep micro 18 at 62 lbs, a full bed of isospeed spin 17L at 50 lbs, and a full bed of msv focus hex at 58 lbs) so for a flat hitter looking for comfort and control these strings are perfect but they don't provide enough spin for my game. Otherwise I would use this string because of how much I enjoy the very muted, firm but arm-friendly feeling of it. I also tried it in a Prince Original Graphite Mid (very open 14x16 string pattern) at 62 lbs with Babolat string savers over the entire bed and that is where this string shined for me. The open string pattern and the teflon string savers allowing the strings to snap back gave great spin, control, comfort, and durability so far. Definitely a winning combo there between the open pattern, the string savers and the 15l nylon makes it play like a stiff poly for spin and control but it's very gentle on the arm and comfortable. But because the babolat string savers are way too expensive I will go with the thinner strings in my Wilson Pro Staffs and restring them more often. I noticed when stringing that this thick string responded a lot when pre-stretched on the crosses. I think this is because at the high tension I was stringing it at friction was preventing it from pulling the cross strings through and getting the proper tension throughout the string. This string is heavy and will have a slight effect on the weight and balance of your racquet. A 40 foot set weighs .8 ounces vs .6 ounces for my gosen 18 gauge string. I would recommend this string highly for the right situations: to a flat hitter who wants a durable, low-powered, and comfortable string, to someone who is playing with a very open string pattern and using babolat string savers to increase spin potential and not have to straighten their strings, or to someone who breaks strings and wants something comfortable. I would not recommend this to someone whose game depends upon loads of spin or who wants lots of power from their strings.
From:Brian, 4/4/17

Comments: I've used this string for more than 3 years, mostly used for chronic string breakers. This evening, I've finished testing the "Quality Index" on a number of strings including ProForm Tuff 15L. To my great surprise, this string out scored all the expensive high end multifilament strings and famous synthetic guts. Tension retention should be very good. The high elasticity of this string is responsible to all the positive comments so far. Highly recommended. (By the way "String Quality Index" is the ability of a string to recover stretching when the tension is removed. The higher the number, the better the string is. An average natural gut scores about 0.8, a good poly scores about 0.6, a high end multis score about 0.75. ProForm Tuff scored 0.77!)
From:Mike, 10/15

Comments: This is a great deal for someone looking to hybrid. I haven't ever played a full bed of nylon or synthetic so I can't comment there, but this stuff takes the harshness out of stiffer polys. In fact, I bought this on a guess that it might be similar to OG Sheep Micro as I had almost finished my reel of that. To my surprise, this is called OG Sheep on the package. The only difference I can tell is fewer strands in the outer wrap (maybe where Micro gets its name?). It plays nearly identical, maybe a little softer (this is also a 15L vs the 16 OGSM I had). All in all, this is great value for the money. It is now my standard cross with BHBR as the main. Great setup and only $24 for 16/32 racquets!
From:Dan, 12/12

Comments: I got these strings not in reel but in package of 12 sets for $18. Good strings. I do like certain strings(but they cost much more) more than these, but I do like ProForm Tuff 15L too. Do not want to deal with reel, would be great to have that package of 12 sets available again. Strings are moving. Hold tension well (losing it just a bit, you can feel it but it's totally OK. It is not like Luxilon, which suddenly can become completely unpredictable). The best price.
From:Bedrock, Santa Barbara, CA, USA, 08/10

Comments: This string lasts me for about 6-7 hours, which is below average for me. I didn't complaint about the playability. It is nice and crisp!!
From:Albert, Montreal, QC, Canada. 4/10

Comments: Two years later.. So, going back to this string after a little bit of a break, I realize that it does not offer nearly as good of a bite as I thought. A very unforgiving string for people looking to create spin, but a beauty of a string if you are a flat hitter. The basics have not changed: if you are just starting out stringing for yourself and playing, definitely get this as it will save you some bucks. If you are looking to create consistent spin and want a bit more bite on the ball without it sailing long, and if don't mind spending a little more, definitely try some other stuff out.
From:Abel, Lawrenceville, GA, USA. 7/09

Comments: What a great buy. I played with it today and felt that it offered good control and nice bite. The power was similar to other syn guts used in the past. I like the firm feel from the string. It was easy to flatten or spin the ball. I am really pleased with the purchase.
From:Anon. 3/09

Comments: This string is really good when used for crosses at 58 tension with Polylon Ice 16 gauge also at 58 tension.
From:Anon. 12/07

Comments: Pretty good string, been using it for around 5.5 months now and it's got some good qualities. The pop mentioned in an earlier comment is true, though I like the sound as it allows me to know when I'm hitting the ball correctly on my groundstrokes/serves. I hit with a lot of spin and am a consistent string popper, so when I first got my stringer and this string I was in awe at how long it would last. Strings generally take about 1 and a half weeks before it breaks at about 2-3 hours every other day. The string really makes you work to create a ton of spin and power, but once you get used to it, you realize how incredible a string it is for the price. The feel on volleys with the strings isn't the best, but it's manageable. Prostaff 6.0 95in @ 63 lbs, and I really recommend this string to anyone who just got their first stringer and isn't picky/looking for a string that they can get used to for cheap.
From:Abel, Lawrenceville, GA, USA, 01/07

Comments: This string is a great string for durability. I can usually break 17 or 16 gauge in a few days, but this last. It has great feel and pop the first 150 hits at the most and then is dead to wear you may have to cut it. The string will be explosive and uncontrollable. I have been waiting for my string machine to come and I didn't want to keep spending to get my racquets strung so a friend of my gave this to me and bet me it would take 3 months to break and it has not. The guy who had developed this string for Gosen told me its like a tournament nylon but when they made it the only purpose of it was to keep the ball from going through the stick. Great price but they last no more than 3 hrs of play.
From:Sal, NJ, USA. 12/06

Comments: This string seems very soft and flexible before stringing, and I was surprised how easily you can bend it with your hand compared with other strings like Sensation 16. But, after stringing it up on a pro staff 6.0 at 60 lbs its actually pretty stiff. It does not feel like 15 gage, more like a regular 16. It's 1.30 mm thick. These strings tend to make a very loud popping noise, especially when you serve which can get pretty annoying. I recommend this string to any one looking for something cheap but durable. You can smack balls all day long with this and it wont break. Of all the cheaper strings out there, like the generic synthetic guts, this looks like something to try at least once. Its amazing how much you can get out of this - and how long it lasts. It's actually pretty soft on the hand - amazing stuff. Give it a try for yourself, and see what you think!
From:Lev, Dallas, Tx, USA. 12/05

Comments: This string did not give as much bite, feel & power compared to the more expensive synthetics. But after playing through the 1st set, I started getting the hang of it. These strings are actually pretty good.
From:Rommel, Manila, Philippines. 12/05

Comments: This is a great string for it's price. Very durable compare to most synthetic gut and the feel is not so bad. The white and gold seem to be more playable compared to the natural and green.
From: Hung, Los Angeles, CA, USA. 04/05

Comments: This string is great value for money & for a 15L string has surprisingly good touch & feel. I look for tension retention as well as playability so it is usually hard to find the right combo of the two. The ProForm Tuff is as close as I have come so far.
From: Andy, London, Great Britain. 3/04

Comments: I like the playability of this string better than most 16 gauge in the same price bracket. The tension retention is very good and the bite is better than the OG sheep 16g. Although, I would think twice before using this on a 95 sq. in. or smaller head size racquet with a 16 main. I use a Prince 730 with a 97 sq. in. head size and a 14/18 main/cross. So if you regularly break you strings on your Babolat Pure Drive (100 sq. in.) or any oversize racquet, you should give this string a try, just don't string it with a tension that's too low or it will have a trampoline -effect.
From: Jerry, Los Angeles, CA, USA. 3/04

Comments: I have dinked my way into the finals of three tournaments with this string. This string has feel and touch, its incredible. You need to try it. It's magical nylon and it has made me a magical player.
From: Crawford, Lake Placid, New York, USA. 2/03

Comments: My coach at St. Michael's College said that I should switch to this string in order to improve my dink shots. This string is a dinker's dream. The feel is amazing. It will last forever.
From: Luke, Burlington, VT. USA 1/03

Comments: ProForm Tuff 15 string is the best. I have used Wilson Sensation 16, Prince Synthetic Gut, and many more. These strings do not break for a long time. They are very sturdy strings!
From: Aram, Los Angeles, California, USA 4/02

Comments: This is the best string that I have played with ever. With this string I got sponsored by Wilson and I am ranked 3rd in the USTA for 14 and unders. I recommend that you use this string for all of your play.
From: Minh, Los Angeles, CA. USA 6/01