The Hobie Mirage Drive GT Sprocket with Rod Bearings is a replacement Mirage Drive sprocket for the new 2015 GT drives. The sprocket includes the new Glide Technology rod bearings, which helps increase the efficiency of the drive by about 15% over the older V1/V2 Mirage drives. This sprocket can be installed on V2 drives but not V1 drives. It does not come with the fin masts or fins. Sold individually.