Screen Print Directs hinge clamps were built with ease in mind. The large adjustable knob makes tightening and loosening easy and painless. Made to be durable the clamps 10GA laser cut solid galvanized steel construction will continuously hold your frame down tight for perfect registration. The clamps 3in adjustability gives you the flexibility you need for off contact. Great versatile clamps for t-shirt, poster, canvas, paper, and flat stock printing.