This is a front-mount Rectify Series drop-in speaker system for Athearn Genesis SD70ACu and SD80/90MAc locomotives. The speaker replaces the front weight located behind the cab and mounts with a little double-sided mounting tape.
 
This speaker can be used singly or combined with the rear-mount AHGS-UNI1. If only one speaker is desired, I recommend this speaker as it sounds a little deeper and locates the sound more centrally, where the prime-mover, horn and bell are located.
 
The speaker comes fully assembled and tested.
 
Overall dimensions are 18mmH x 18mmW x 30mmL