This is a Rectify Series drop-in speaker system for Life-Like Proto 1000 F-Unit locomotives. More than just a box, the enclosure features Diapasonic Tuning™, which allows the lower frequencies to accurately develop and resonate, clears the midrange of excess resonance and tunes the upper-mid/high response. The speaker uses the rear screw/pin-mount of the stock PCB to mount in place. You can then install either a PCB-style decoder (such as a Loksound Direct or Tsunami2 PNP), use a motherboard+21-pin decoder or hardwire a decoder.
 
The speaker comes fully assembled and tested.
 
Dimensions are: 15mmH x 20mmW x 42mmL