Replaceable jaw inserts hold rings securely and without marring for stone setting, filing, and finishing. Lighter for hand than the BenchMate® holder so ideal for hand use. Machined from aluminum and steel,  the tube is aluminum and the jaws are steel.  Jaws open to 8mm (5/16″) wide to fit a ring 8mm. Overall length is 7″ (178mm), tube diameter 1.25” (32mm). Weighs 1lb (.45kg). Made in USA.