MIL-SPEC (short for Military Specification) refers to the military standard from the U.S. Department of Defense. The Luminox 3350 series watch is built against the performance specifications standard of MIL-PRF-46374G. This means its design and colors, water resistance, robustness, quality, and material sourcing reflect the standards of the U.S. Department of Defense. This watch is a must-have watch for military, first responders, the rugged outdoors, as well as true sports lovers who want a unique watch that they can rely on, whether on land, sea or in the air. Packaged as a set, the MIL-SPEC comes on a black rubber strap with CARBONOX™ signature buckle .