This tMA-44 Clip-On Adapter allows the Swarovski tM 35 Thermal Monocular to be very easily converted from a handheld device to a clip-on device. Together with your 44mm objective-lens riflescope, the thermal imaging device creates a powerful combination that requires no sighting in and guarantees a 100% reliable point of impact, each and every time. The tMA thermal monocular adapter is compatible with SWAROVSKI OPTIK Z8i, Z6i, Z5(i), and Z3 riflescopes.