Heuer Polyurethane Prism Magnetic Protective Jaws - Heuer 108120, These protective jaws from Heuer have been designed for clamping sensitive round and oval workpieces. The in-built prisms in various sizes allow the workpieces to be held securely. Heuer 108 120 Polyurethane Prism Magnetic Protective Jaws - Jaw Width:120mm