The Sunwayfoto QRS-01 with D-ring UNC1/4”-20 Screw for Quick Release Plates is a special screw to allow fast and easy mounting and dis-mounting of most quick release plates. The D shape can support a max load of 50KG and can be used to attach straps, hand grips and anything else that will attach to the D shape. It’s made from 303 stainless steel so it’s tough and has a very high corrosion resistance.