Jet 52804 4-inch Double Header C-Clamp Opening Capacity Max.: 4 " Throat Depth: 2 1/8 " Nom. Clamp Pressure: 1,500 Lbs Overall Dimensions: 4.5"HX1"WX8"L Height: 4.5 inch/Width: 3.9 inch/Length: 8.5 inch