These guides are made from extruded aluminum for light weight and maximum durability. * The unique 2-3/16" wide tube rail construction keeps the ProGrip Clamps more rigid . * Triple cam lock lever for securing your stock or your clamp to the table top surface. * Includes tape measure scales, low profile jaws and built in T-Track on the top side. * Available in 24", 36", 50", each sold separately.