Rotary Clamp 3EXC45 is used to fasten components at random positions where they cannot be fastened directly to the optical table. Screw a post or post holder onto the clamp's knob. Then locate the component at the required position. While the knob is firmly attached to the component, it allows the plate to rotate freely. Position the plate's slot over a tapped hole and screw it down to clutch the knob. The component will remain stable. Material: steel with chemical black finish. Weight: 0.08 kg