4, Light Duty, UStyle Bar Clamp, Rail Is Made Of Quality Steel Drawn In A Single Piece For Durability Strength, Sliding Arm Is Made Of Die Cast Zinc Which Is Light, Stable Break Resistant, UShaped Rail Enables Step Over Clamping For Those Hard To Reach Spaces, Plastic Pressure Caps On The Top Bottom Sections Protect The Work Piece Surface, 4 Clamping Capacity, 2 Throat Depth, 330 LB Clamping Force