Routes the larger 1 1/4" X 8" faceplate opening used on Adams Rite MS 1850SNSI lock. Requires HIT-45 Clamp and router equipped with 3/8" outside diameter guide and 1/4" router bit for aluminum doors. For wood doors use a 5/8" outside diameter guide with a 1/2" flat bottom router bit.  (Part # for our 1/4" router bit HIT-45RB4)