When used with a chest strap and the Ascension rope clamp the croll makes for a simple and efficient system for ascending fixed lines.The angled attachment hole keeps the device properly aligned on the chest. Chrome plated steel cam with angled teeth and self cleaning slot securely grips the rope, even in muddy or icy conditions.The cam engages without losing a millimeter each time it is weighted and glides smoothly up a rope with minimal effort.Ergonomic trigger allows one handed installation and removal of the crollWeight: 130gFor use with ropes between 8 and 13mm