The rope grabs utilize a cam /ever as well as a friction sensitive brake to lock the rope grab onto the lifeline in case of a fall, even if the operator holds the device open in a panic situation. They will also reduce the arresting forces on a worker if there is a fall. Mobile design automatically follows the user Manual option allows the user to fix in place Cam locking system for safety Detachable anywhere along the lifeline Durable and lightweight corrosion-resistant construction For use with 5/8 (16 mm) diameter polyester/polypropylene blend rope lifeline Use with 3 ft. (0.9 m) shock absorbing lanyard Features: Mobile design automatically follows user - Provides hands-free operation automatically the following user as they ascend or descend providing maximum freedom of movement. Manual option allows the user to fix in place - User can place in static mode which fixes the device in place unless the user manually moves the grab up or down the lifeline, making it ideal for restraint or work positioning applications. Cam locking system for safety - A simple yet extremely effective brake system utilizes a cam lever to stop a falling user and maintain safe fall arrest distances and forces. Detachable anywhere along the lifeline - Allows the user to attach or remove the device anywhere along the rope lifeline for greater job site flexibility. Durable and lightweight corrosion-resistant construction - A zinc-plated steel build will stand up to the harshest environments for added field longevity. For use with 5/8 (16 mm) diameter polyester/polypropylene blend rope lifeline - Fits the most common rope size for rope grabs - order 50 ft. (15 m) lifeline 1299997 separately, other lengths available. Retails for $160