Pyser Optics Francis Barker 1605 NATO Luminous Brass Escape & Evasion Compass. NATO Stock Number (NSN): 6605-99-265-1167. New. Made in England. British military specification Escape & Evasion aid. Brass body construction with a glass window. Black protective paint coating. 15mm in diameter, 5mm thick. Two luminous markers and red paint indicates north, one luminous marker indicates south, enabling clear orientation in darkness. Niva alloy (chrome,cobolt and valadium) and brass pivot. Operating temperature: -40C to +55C. Weight 2.9 grammes. Often sewn into clothing or hidden on the body for concealment until required.