NOT self tailing ... don't waste your money
I know stu loves 'em because this discussion comes up once in a while, but I was very disappointed when I had mine. The outside edge of the device is designed to cleat the line, like an ST winch and it works okay. I recall that was the part Stu really liked, but don't quote me. For winching, the drum must be completely loaded for the rubber rings to grip the line, however, there is no stripping arm (that's what makes ST winches so expensive) to peel the tail of the line off the winch. So, do not expect the wincher to convert your winches to self-tailing models... no way.I had some on my halyard winches, but after a year of trying to like them...they just seem to be in the way. Since I didn't really need another cleat I took them off and gave them to my neighbor, he has since given them to someone else. You can use them to make small adustments, a half turn or less, but you can't reel in a jib sheet or hoist a sail without grinding and tailing with two hands. For that reason, I wouldn't recommend them for sheet winches. First you'll have to have the drum completely wrapped, as previously mentioned, which is usually unnecessary in normal conditions. Second, stripping off the sheet when tacking is difficult because you can't just pull up on the sheet, you have to uncoil it from the drum.... SLOW SLOW SLOW and you always need two hands........ so what's the point?Finally, sometimes you can find the things on sale or at clearance counters...not at West Marine... I found mine at Minney's for $8 a piece.