All Supa-Peg ridge rails have inserts made from High Impact Nylon and first designed by Supa-Peg in 2003. They are extremely strong, leave no sharp edges at the end of the rail and are keyed in on all four sides to hold them securely in place. It also allows more of the spigot to be utilised by ropes and other spreaders without the risk of them falling off. They are made from anodised hard structural 30x32mm extrusion.