These screen printing hinge are made of zinc alloy, chrome-coated surface, they are durable and rust resistant.The feature two holes that you screw directly into your workbench and wide-wing thumb screws to your (screws is not included).These also feature positive locking for perfect registration.The screen print butterfly are used for fixing screens when printing. It can hold all wood or metal screens from 0.5 inch to 1.8 inch (12 to 45 mm) thick, Height: 3.3 inch (85mm), Length of Clamp: 2.4 inch (60mm) They are used to your screen to a table or work surface, easy to install and positive locking for perfect registration.For , new beginners to learn how to screen printing. The screen printing hinge clamp is the fastest way to a printing press.Material: Zinc alloycolour: silverPackage Contents:2 x Butterfly Hinge ClampOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.