Olive drab painted metal storage case with hinged lid and latch closure, fitted with canvas handle. Stenciled military markings on exterior identify it as “Case Spare Valves No. 4L.”
The interior contains fitted foam and fabric compartments designed to hold radio valves (vacuum tubes) and electrical components. The underside of the lid includes a printed diagram indicating proper storage arrangement for each part, including items marked “ZA” and “WB” with individual reference numbers.
Inside, several radio valves remain in place, including examples marked Westinghouse Radiotron and glass tube valves. The removable inner block is covered in khaki canvas and secured with a fabric pull strap.