Please note: If the filter drawer is used with the ToupTek OAG, you can be assured there will be no visible light leakage, even after stretching images with 600s exposure time taken during daylight. If the filter drawer system is used only with other adapters and not the OAG, it is necessary to cover the OAG screw holes to ensure there is no light leakage. Plugs for the holes, screws and a mini-screwdriver are included in the Housing + Holder kit and the Housing Only kit.