Luxilon M2 Pro 125 is an all new string that uses multi-mono technology to provide the playability of a multifilament with the durability of a monofilament. This technology creates M2`s variable flex for more comfort on soft hits and more control on hard hits. All of the benefits of a hybrid - now in one string. Use Luxilon M2 Pro for added playability vs. Luxilon M2 Plus for added durability.