These strings are all about spin. They bite, and they impart spin. I use these on the Prince Triple Threat Warrior Mid Plus racket (spin friendly) at 57-58 lbs. I generate nasty slices and and kicks and get compliments from 4.0 and some 4.5 players. Sometimes the spin I generate leaves me with my mouth open in disbelief. Power is adequate, although with this racket, I need to generate my own power. I have a very quick swing which also helps with the spin. If you are all about spin, these are a great value for a spin friendly string. They last about 6-8 in singles play with a lot of base line rallies and hard serves, and that probably fluctuates 2-3 hours depending on the players style. BTW, if you are thinking about getting a Focus Hex, 18 guage, I'd suggest going with this one instead. I am a 4.0.