7 series single block with Stainless Steel cheeks and snap shackle attachment. Delrin(tm) sheave ensures smooth operation and high safe working load. Swivel head with Snap Shackle may be locked in place to avoid twists or allowed to swivel. Delrin Sheave, Aluminum Cheeks. Length 5 13/16"(148mm), Width 2 1/2"(64mm), Thickness 1 3/32"(28mm), Weight 8.6oz (244g), Max Line 1/2" (13mm)