Fusion Climb Advent Speed Super Stainless Steel Pulley 50KN 1 Advent Stainless and Alloy Steel Pulley Sealed ball bearings, long wear alloy sheaves, 2 attachment points (primary and back-up). Strength: MBS:50KN Dimensions: 4.19" x 4.51" x 1.38" Designed for extreme and continuous service in permanently rigged challenge courses, commercial ziplines and eco-tourism application