For bigger sails, bigger folks, or if you just don't want to switch out your extensions to RDM - an SDM (standard diameter mast) is the way to go. The Goya 70% carbon windsurfing mast is a great combination of light enough, durable, and not too expensive! When you ride this mast you can be at ease that it has undergone the same quality control standards that every other Goya product has to live up to. You ride what we ride. And we like our gear to deliver and last.