The modification involves physically removing the “hot plate”, a kind of filter that blocks infrared light. Manufacturers install it in cameras in order to correct for the reddish hue inherent to CCD or CMOS sensors. Removing such filter makes the camera more sensitive to IR and as well as H-alpha wavelengths, which is particularly useful in deep-sky photography.
This Kenko NES tracking mount is classified as an EQ3 mount. I got this mount from a surplus shop in relatively good condition but without the motor controller and counterweights, and sold “as is” with no assurance that the motor will work since it is already 2 decades old (1990 model)! Read more.