Type A-11 Navigation (Hack) Watch, No. 10616 manufactured to Specification No. 94-27834-B by the Waltham Watch Company, Waltham, Massachusetts.
The type A-11 navigation (hack) watch (see figure 1), consists of a waterproof, chromium plated brass case with one piece center and bezel, fitted with a round unbreakable crystal, stainless steel threaded back and waterproof winding crown, containing a 6/9-size, 16-jewel grade center second movement.
On a latter mode (see figure 2), the waterproof case has been substituted with a dustproof, three piece type consisting of a chromium plated brass center and threaded bezel, fitted with a round unbreakable crystal, stainless threaded back and waterproof winding crown.
A waterproof wrist strap is attached to the case by means of removable spring bars.
The hands, numerals and graduations are painted white, and the dial has a durable dull black surface. The dial is graduated into 12 hours, corresponding with one revolution of the hour hand. One revolution of the minute hand equals one-hour, and one revolution of the center second hand equals one minute.
The winding of the watch is accomplished by rotating the winding crown in a clockwise direction. It should be fully wound at least once every 24 hours, preferably at approximately the same hour.
The watch is provided with a second setting mechanism which permits setting of the center second, minute and hour hands correctly with a master time source. When the winding srem is pulled into setting position, a flexible spring contacts the balance wheel and stops its movement, allowing the minute and hour hands to be set. The watch will again start to run upon pushing the stem into winding position.