They are made from phenolic or nylon plastic and come in inch and metric sizes. The phenolic-plastic version has a black handpiece with a smooth glossy finish. The nylon version sports a smooth matte finish. Both handles have threaded zinc-plated-steel spindles with an internal hexagon for mounting. Stainless-steel spindles are available in metric sizes only.
J.W. Winco Inc., Box 510035, New Berlin, WI 53151, (800) 877-8351, jwwinco.com