Mulco Sub Second Bumper / Hammer Automatic Swiss Made Men's Watch. Early WWII era, late 1930?s / early 1940?s. All original an unmolested including the often replaced steel crown. All steel diver case measures 30.5mm without crown. Movement is believed to be an A. Schild 1171. It is a bumper automatic watch movement, which was introduced in 1935 and used until 1945. It is an early version of the AS movement series and was a redesign of the Harwood automatic movement. It is a hammer / bumper automatic movement. Fully functional. Comes on a period correct NOS strap. Mulco was a watch brand established in 1931 by Mühlmatter Grimm of La Chaux-de-Fonds. It remained active through to 1995. During WWII they supplied watches to the Third Reich.