Excellent coverage here;
http://www.royalsignals.org.uk/key-p...yandplugv1.pdf
There is mention of a British, Ausy and the New Zealand copy of the 'key slide'..
The NZ unit is a locally produced "Key WT 5 amp No2" .
The associated Slide was designed for the ZC1 Mk I & MkII in the vehicle mounted role.
here is mine;