I've built two cameras using the MS20 detectors. On one I mounted the IR detector outside the camera enclosue in it's original package. On the second I glued the fresnel lens to the inside of the camera enclosure. The IR detector board is epoxied to a scrap of Lexan sheet slightly larger than the board to give some space for mounting screws. The board is mounted inside the camera enclosure on four 2" long 6-32 machine screws. Each screw is set up with three nuts; one where the screw passes thru the enclosure and one on each side of the Lexan sheet. Using this arrangement I can adjust the distance between the IR detector and the Fresnel lens. I have mine set at about 1". The benefit is the IR detector sensitivity can be tuned so that the detection range, camera range and flash range are all about the same. The camera with the IR detector in the original housing is more sensitive and tends to have a lot of photos with no game visible. Where the camera with the adjustable spacing between the IR detector and the lens has very few.