The is a drop-in Rectify speaker for Atlas Classic EMD AEM-7 locomotives. The speaker installs in the roof-top radiator. Simply pop the top casting off by pressing the four pins inside the shell. Enlarge the hole in the roof enough to let the wires easily pass through. Solder wires to the speaker, press the speaker into the radiator casting, feed the wires through the hole and snap the casting back onto the roof.
 
You can then either use a small 8-pin decoder decoder plugged into the stock motherboard or replace the stock board with a Nix Trainz Decoder Buddy and 21pin decoder.
 
The speaker comes fully assembled and tested.
 
Dimensions: 6mmH x 19mmW x 23mmL