The Allen 20mm Dynamic Flip Flop Block with A..77 Cleat is equipped with a pivoting mechanism that keeps the rope close to the deck, mast, or boom while maintaining low friction and guiding the rope to the intended location. It features a relocatable sheave with two installation options, dynamic bearings with stainless steel ball bearing technology for durability, and a removable clevis pin for easy access. The block also includes a small ball bearing cam cleat with optimized jaw profile for reduced rope wear and a smooth cam action. This versatile block is ideal for halyards, pole launchers, and control lines. See the included PDF for detailed dimensions.