Hi everyone, First post! I played quite a lot of tennis 6-7 years ago and for whatever reason had to stop. But I have been really getting back into it recently. I had been using a Hammer 6.2 for the most part over the years. Last week I purchased a Steam 99s and put on the recommended Luxilon 4G at 57 and noticed it had way more of a "pop" than when I demo'd the racquet (from a different store than where I purchased it). The demo had a string that I really liked. It had a much softer feel and I felt like all my shots had way more spin with it and were much easier to keep in. I called the store and they didn't seem too sure what it was when I asked, they said they didn't carry it. I know I don't have too much to go on but I can tell you the sticker on the frame said ESP (could mean absolutely nothing) and that they were green-ish/lime green. Thanks, any help is much appreciated.