From the Manufacturer
For best performance, use this system with biscuits or dowel rods. The easily interchanged angle adapters give you a high degree of flexibility with adjustable clamping up to 4 inches wide. This system features a black oxide locking device, non-slipping, non-marring polyurethane jaw faces, and fiberglass reinforced polyamide clamping device and clamping jaws able to obtain clamping pressure up to 770 pounds. Adapters for 22.5-, 30-, 45-, and 60-degree miters included. Bar clamp not included.