Proprietary Technology that utilizes tiny micros gas light tubes to luminate even in complete darkness. Unlike other watch brands that use a phosphorescent paint which requires external light source to produce the luminous effect, this watch does not. For this reason, the Navy SEAL has asked Luminox to develop a special dive watch for their night time missions.It does not require a push button to activate the light, just easy and excellent visibility 24/7, up to 25 years.