Round 7 Shank REGULAR, with 3/8" Low Port.   The Regular shank length is 7 1/4" long.    Mouthpiece is 5" wide.  Shank Material is 3/8" diameter giving this bit more weight.  The Round 7 Shank comes in Blued Steel and Stainless Steel.  As always the 3/8" Low port is steel and includes Copper Inlayed Bars to promote salivation.  NOT FOR GREEN HORSES.  The effect of the leverage is stronger therefore can be more severe.  The reaction is quicker and there is less signal.