Mirage Drive ST Turbo Mast - Threaded for V2 drives. A replacement mast for the ST Turbo fins. It is too long for the other fins. These are very durable, but will eventually work hard and fail if bent back into alignment enough times. So if you're in a stumpy area, having a spare mast is not a bad idea. You'll want to put a drop of Loctite on the mast prior to installation. Hobie uses a Blue Loctite (HC 8000341).