No-Mar manual operated temporary sheet metal fasteners instantly spin up or down with the flick of a finger and require no pliers or installation tools. No-Mar manual operated temporary sheet metal fasteners have a specially designed tip that provides maximum gripping strength and are ideal for close tolerance positioning of thinner layers of material.No-Mar manual operated temporary sheet metal fasteners feature a No-Mar plastic cap and are color coded for easy identification. No-Mar manual operated temporary sheet metal fasteners also known as skin pins, are widely used in the manufacture and repair of aluminum-skinned aircraft and in automotive repair, where it is used to temporarily fasten multiple sheets of material together before the pieces are permanently joined.