Military Specs. FRS/MS 2000M DISTRESS LIGHT MARKER Size: 4.5 x 2.2 x 1.1 in (11.4 x 5.6 x 3.3 cm) Weight: 4.0 oz (115 g) without batteries Visibility: Military tested at a distance of 6 miles (9.6km) on a clear dark night Waterproof: To a depth of 50ft (15.3m)