Kevlar + has some kind of polyfin fibers braided into the kevlar and makes it play a bit "softer" than plain Ashaway Kevlar. You can plainly see the difference between the two as the Kevlar+ has a dark line in the braid. I threw my last set of Kevlar+ away the other day. I have Ashaway Kevlar strung in the mains of probably at least a dozen rackets. I also string a pretty hard hitting D1 female player's rackets with Ashaway Kevlar 16g mains x Ashaway Zyex Pro 17g at 65/59 using my NEOS 1000 lockout. She breaks the Kevlar in about a week to week and a half. She likes that string combo though, better than when she was using full bed poly.