73-37 Reefing slide/block allows the "dead end" of the reefing line to be tied or spliced and led around the boom and through your clew reefing grommet. Slide features our polyethelyne liner for easy adjustment on 1" t-track. Ideal for most boats to 30' (9.1m) Track Size 1" x 1/8" (25 mm x 3 mm), Boat Size Up to 30' (9.1 m), Bail Width 5/8" (16 mm), Bail Height 1-1/16" (27 mm), L 3" (76 mm), W 2-7/16" (62 mm), H 31/32" (25 mm), Weight 4 oz. (113 g)