This is a Rectify Series drop-in speaker system for Atlas Classic & early-run Master U30/33/36C/C30-7 locomotives.

Two versions available:

Most all versions use the ALCL-GEUC. The speaker is a beautiful press-fit between the rear weight and motor mount. No frame/weight/shell modifications are needed! The factory PCB will need to be removed with either a Decoder Buddy installation or a hardwired decoder. Board-style decoders will not work (Soundtraxx PNP, LokSound Direct), as they take up all of the space between the two weights and leave no room for the speaker.

There is an alternate chassis version that I have only seen twice in 15 years. I do not know when this chassis was produced or why it is different. The speaker still mounts between the rear weight and motor, but the rear weight has a "shelf" and provides more length than the common version. This is the ALCL-UCV2 speaker. See second set of photos.

The speaker comes fully assembled and tested.