Barton Marine Size 4 Wincher, Fits 3-1/2"â€“4" Drum Diameter. Winchers are rubber disks that fit over the top of your non–self-tailing winches to make them perform like self-tailers. Loading up the winch drums until the line contacts the underside of the Wincher creates friction which allows the line to self-tail. A rope groove holds line reasonably securely around the top of the winch. Practical Sailor magazine recommends Winchers for halyard winches but not for sheet winches, although many of our customers swear by them. Note: Sizes are drum diameter, not the top or base of the winch. Sold in pairs.