The new TR-660 is a Type B self-winding wrist watch (submersible). Replacing the TR-900 MIL-W-22176A (SHIPS). The TR-660 features improvements including the use of a proprietary non-radioactive Super LumiNova luminous paint for longer service life and broader operational environments than legacy luminous materials. The Japanese made NE15C movement delivers a longer power reserve and superior accuracy to the preceding mil-spec. Water resistance has been improved to 660 feet and the construction enables longer service intervals. Lastly the TR-660 has optional aluminum or acrylic timing dials and reinforced spring bars to meet the ISO standards for dive watches.