Motor board bridge 4736 for the Model 700, 768, 760. Color: Grey. Replaces part AA-4243. Length measures 15-1/2", width is 6-3/4", and 4-1/4" high. This part mounts to the motor board orifice plate (RP-4244). The motor (RP-4237, RP-4031) mounts on this housing.
Identical the the earlier beige version (AA-4243), Aprilaire just updated the color.