b'40 mm BlocksAbout Carbo Air blocks: see feature page at beginning of this section. 2156Tiwal 2, 2.79 m (9\'2"), naval architect: Marion ExcoffonTiwalHigh-strength pivoting lead blocks with cams are used for halyard controls on larger keelboats and as headknockers on dinghies and beachcats for sheeting directly from the boom. Hole spacing and rivet size are the same as Classic models, 2157 making upgrades easy. Cam reverses for either up or down cleating. 2638 2639 2640 2641 26422643 2647 2648 2654Sheave Shackle pinMax line Maximum Breaking PartLength Weight working loadloadNo. Description in mm inmm oz g in mm in mm lb kglbkg4 1/2 2156Pivoting lead block/150 Cam-Matic* **1 9/16401126.61863/810300136950430 2157Pivoting lead block/365 Carbo-Cam* **1 9/16404 1/21125.51573/810200919504302638Double/swivel1 9/16403 11/16943.2863/1653/810970440238010802639Double/swivel/becket1 9/16404 5/161103.4903/1653/810970440238010802640Triple/swivel1 9/1640944.61183/163/810145566030501383 3 11/1652641Triple/swivel/becket1 9/16404 5/161104.71223/1653/810145566030501383xed 2642Double/ 1 9/16403 1/2892.8803/1653/81097044023801080 2643Double/ 1 9/16404 3/161062.9843/1653/81097044023801080xed/becket 2647Triple/swivel/471 Carbo-Cam**1 9/16403 11/16948.22323/1651/4675034015006802648Triple/swivel/471 Carbo-Cam/becket**1 9/16404 5/161108.32353/1651/4690040818008162654Quad/swivel1 9/16403 11/169461703/1653/810145566030501383*Can be used as becket block.**Maximum working loads and breaking loads for blocks based on cam strengths.21'