The T.3180 ‘Walter MK.1’ transmitter, stores reference 10DB/975 was a compact portable homing transmitter designed to help locate downed airman. It was fitted with a telescopic aerial mast and integral dry-cell battery power supply that emitted a pulsed signal that could be received over a range of up to 20 nautical miles by airborne ASV Mk. II radar sets or Rebecca Mk. IIb equipment fitted in Coastal Command and Fleet Air Arm aircraft. In use the telescopic mast extended to a height of approx. 6 ft. and was fitted with three guy ropes that secured to the K-type dinghy sides. The lower section of the unit was held between the airman’s knees with a felt pad fitted to the base in order to prevent slipping and damage to the dinghy floor. To preserve the battery it was recommended that the transmitter be operated for 15 minutes at a time at five-minute intervals and only intermittently until an aircraft or rescue craft was sighted. This example is in superb unissued condition with instruction label, cellophane and and the box of issue. Extremely rare and saught after. Stock code S18311.