Improved features enhance handling and help shooters reload faster in action shooting events. GM-45CS ?Specialx9D has no thumbrest and features a ?sculpturedx9D cutaway so the thumb reaches the magazine release button quicker. GM-45C has flat sides, with no thumbrest or cutaway. B-HP/CG has flat sides, the sculptured cutaway, plus front finger grooves for positive finger placement. B-HP/C has only one flat side (left side), right side has raised portion near top of grip panel. Mfg: Pachmayr SPECS: GM-45CS ?Specialx9D and GM-45C fit 1911-style Auto except Officers ACP. B-HP/CG, B-HP/C fit Browning Hi-Power.