Solid Stainless Steel Housing is machined out of a solid billet. Components are strength hardened for durability. Smooth pull every time. Works with shaft sizes: 9/32 5/16 & 3/8. Mechanism housing has a rounded section for easy installation. The perfect mechanism for building your own speargun. Dimensions are 1"H - 2.75"L - .5W Stainless steel pins and line release are included.