Another one in the Series Types 30, 53, 5G [TX only], 64 and 65 ?  Yes, another Portable radio transmitter and receiver.

Handbook, BR 1366 dated December 1941 - Pearl Harbour and the USA entry into WW2!

The transceiver, together with the HT and LT batteries are carried in a haversack.  A pocket in the haversack contains the telephone handset and a 10-foot length of aerial wire. For all round maximum range the aerial should be vertical, the free end being thrown over or secured to some suitable object.  If this is not possible, the aerial can be laid out in a straight line on the ground.  The aerial may also be trailed when on the march.

The HT battery is a 99V wet-cell which should last for 100 hours and the LT battery, a cell of 1.5V, 50 hours.  This assumes a 10:1 listen/transmit ratio. The range is said to be 2 miles over the sea with a trailing aerial and 8 miles over the sea with a vertical aerial.

The transmitter is amplitude modulated [AM] and has three [fixed] SPOT FREQUENCIES, namely 22.5 Mc/s, 23.5 Mc/s and 24.5 Mc/s.  The receiver is free tuning over the band 22 - 25 Mc/s with corresponding calibration marks to match the three spot frequencies of the transmitter.

If more than two sets are worked at the same time within half a mile of each other it is possible that the interference caused by the receivers will prevent good communications.