Water Proof WATCH CASE OPENER +2 How To Books This is a new screwback case opener It opens and closes screw back water resistant watches without scratching It includes 12 patterned pins / grips, 4 sets in all, for a variety of case backs This adjustable case opener can open Bulova, Rolex, Movado, Gruen, Longines and Accutron screw type back waterproof watches It measures approximately 5 1/2" (140 mm)