This is a Rectify Series drop-in speaker system for Athearn RTR SW1000/1500 locomotives. The speaker uses the front PCB mounting screw. The only modifications required are to nip-off three little unused plastic nubs on the inside of the shell. Room is provided for front lighting. Decoder installation is simple with a Nix Trainz Decoder Buddy (available here https://www.scalesoundsystems.com/product-page/nix-trains-decoder-buddy-motherboard) and 21-pin decoder or by hardwiring a decoder.
An insallation guide is available under the "Guides" tab or here: https://docs.wixstatic.com/ugd/7e84c8_d8dbe7baa65142ff9c11843937397eb2.pdf
The speaker comes fully assembled and tested.
Dimensions are: 8mmH x 17mmW x 26mmL