Fits all Cogsdill style 50100 2 Axis CNC Heads. For 55 degree inserts with 3/8 IC positioned at a 17.5 degree angle. Similar to 50100-375ICD-55-17.5-COG with insert pocket closer to machine center line. Holders of this style can be made to hold any style of insert in any position withand with out coolant and removable cartridge.