Model Part Number Backhead Thread
MR120 Hammer 4" Remet MR120AL01 4" Remet
MR120 Hammer 4" Metzke MR120AL02 4" Metzke
MR120 Hammer 4 1/2" Remet MR120AL03 4 1/2" Remet
MR120 Hammer 4 1/2" Metzke MR120AL04 4 1/2" Metzke
MR120 Hammer 115 ARDX MR120AL05 115 ARDX