Tank Modellbau loudspeaker (small) for rc tanks.  High quality, compatible with Heng Long, Tamiya and El-Mod (please note that you will need to remove the battery box if fitting in a Heng Long PzIII or PzIV).  Dimensions approx 70 x 60 x 30mm.  Technical data -

Impedence 8 ohms, max 10 watts, range 150-20,000 Hz.