MIL-S-3720E, MILITARY SPECIFICATION: SKETCHING BOARD, WITH WATERPROOF COVER, TRIPOD MOUNTING (2 DEC 1986)

MIL-S-3720E, MILITARY SPECIFICATION: SKETCHING BOARD, WITH WATERPROOF COVER, TRIPOD MOUNTING (2 DEC 1986)., This specification covers a wooden sketching board with built-in compass, a waterproof cover, and a folding extension tripod.