ID: 
2285
Maker's Name: 
Mullard
Where made: 
Holland
Dimensions: 
3.9 × 2.6 × 1.8 cm

PNP Germanium power transistor in TO3 metal case.

This is an example of early solid-state power amplifier devices.

This device was easy to destroy if the case temperature was allowed to rise above about 90C.