This durable co-poly string is very, very spin friendly. The slick surface of RPM Blast allows the main strings to slide out of alignment, grab the ball and then snap back to add spin to the shot. While all co-poly monofilaments do this to some extent, our lab tests confirm that RPM Blast is exceptional in this regard. Though RPM Blast offers a slightly softer feel than traditional polyesters, it is by no means the softest co-poly available. It is an ideal choice for big hitters with heavier racquets seeking maximum control, durability, and spin. It feels great if you string it on its on or if you do a hybrid. The string has been on the market for a long time and it has proven to be one of the best selling strings in the industry. It is the choice of many big names on the Tennis Tour!