Wilton 540A Series Carriage C-Clamp Kit Kit features heaviest duty carriage clamps available. Includes four clamps of the most popular sizes2 1/2 in, 4 in, 6 in and 8 in opening capacities. Frames are constructed from high strength ductile iron castings. Contains sliding pin (vise type) handle, single acme thread rolled spindle and oscillating ball and socket tip. Suitable for light industrial, woodworking and repair applications Pack of 1