The Hobie Mirage Drive V1 Standard Mast is the replacement steel mast for Hobie Mirage Drives that utilizes a set screw connection in the sprocket. The Hobie Mirage Drive V1 Standard Mast fits the Hobie standard fins that come with most Hobie kayaks as well as Hobie ST fins (not ST Turbo).
I love the Mirage Drive system and have both the Adventure and the Outback in the 2008 model. Simply through use (not impact), I have snapped the metal mast/beam twice where the beam enters the sprocket. I am hopeful that the weak point in the beam is resolved in the threaded version of the beam released in 2009. Regardless, it is worth the hassle and expense to make the repair. It is a wonderful product.