The Big Bullet block is exceptionally free-rolling, with a large 1-1/2" sheave that accommodates up to 3/8" line. Use exit and in-line blocks for turning lines into and out of masts, booms and through decks. Use exit blocks with cams on masts for halyard controls. Upright lead blocks are perfect under decks and at mastbases. The 140 with aluminum 150 Cam-Matic cleat is designed for under-boom mainsheets or for spar-mounted halyards and control lines. The 141 with 365 Carbo-Cam cleat is ideal for control lines.