This is a two-speaker drop-in speaker system for Athearn Genesis P42 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 speakers drop right-in and no modifications are needed to replace the factory speaker. I use a touch of double-sided mounting tape to secure them.
 
The speakers come fully assembled and tested.
 
Dimensions are: 28mmDia x 13mmH
 
VIDEO: https://youtu.be/iYozc0zLfqg