These are Rectify Series drop-in speaker systems for Life-Like Proto 2000 QSI-era hood-unit locomotives. More than just a box, the enclosures features Diapasonic Tuning™, which allows the lower frequencies to accurately develop and resonate, clears the midrange of excess resonance and tunes the upper-mid/high response.
 
Two speakers are available:
 
The LLPR-QSI1-RC1 is a half-round shaped system that fits within the a-frame speaker mount and fires down over the drive-shaft. If your a-frame opening measures about 25mm in diamteter , these will work. The GP30s have this smaller opening. No modifications are needed to install the speaker.
 
The ALMA-QSI1-RC1 is slightly larger at around 27mm in diameter. I have found that these fit the RS27s.
 
Simply remove the stock speakers or cover-plates on non-sound units and use strips of double-sided mounting tape to secure the Scale Sound Systems speaker within the frame.
 
The speakers come fully assembled and tested.
 
Dimensions are:
LLPR-QSI1: 16mmH x 18mmW x 25mm Dia.
ALMA-QSI1: 16mmH x 18mmW x 27mm Dia.