ACT-39 Lens plate with M39 thread for ACTUS-B This lens board allows you lenses (Leica thread) are provided with a M39 thread, such as magnifying lenses to use on the ACTUS camera. The surface of the ACT-39 fits the ACTUS-Titanium version. The use of the lenses may possibly be limited to those which can move freely in front of the camera used in each case.