This is a Coeval Series drop-in speaker system for Scale Trains SD40-2 and Tier 4 GEVo locomotives. The speaker is a beautiful press-fit into the factory cavity and no modifications are needed to replace the factory speakers.
The speaker comes fully assembled and tested. Please choose 4Ω (Loksound) or 16Ω (Soundtraxx) wiring.
Dimensions are: 12.5mmH x 16.5mmW x 34mmL