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