The HepcoMotion ALR aluminum ring from Bishop-Wisecarver is a rotary movement system for medium precision and light load applications in woodworking environments, or wherever corrosion resistance and a non-magnetic environment is required. Available with external vees and in four sizes (from 148mm to 300mm in diameter), the rings are made of high-strength, anodized aluminum alloy; specialized rings may be ordered. (888) 580-8272, BWC.com.