Protecta RailDog Hi-Vis Sliding Rail Anchor* Installs onto 2 3 4" to 3 1 4" wide rails (7. 0 8. 25cm), fitting most rails and is designed to be used on rail sections from 90 to 141 lbs yd and 132 lb head free rail. * This anchor slides smoothly across the rail, following you as you work, for hands free mobility and fewer interruptions. * The compact and lightweight design of this sliding rail anchor makes attaching to the rail simple and fast. * The high strength and corrosion resistant