This is a Rectify Series drop-in speaker system for Walthers Mainline ES44 and SD70 locomotives. The speaker uses the factory screw to mount and no modifications are needed to replace the factory speaker/weight.
 
The speaker comes fully assembled and tested.
 
Dimensions are: 12mmH x 17mmW x 37mmL
 
VIDEO: https://youtu.be/JrtPbnGlT-E