Long battery life. By stand-by mode, battery lasts 1000h. Power switch remotely controllable. You can control on/off of rcs-50 by rcs-20t. Controllable range is nearly 100m. Original code between rcs-50 (transmitter) and rcs-20t (remote controller) avoid interference with the other unit if someone use it in the same area. bug detectors can not detect sleeping transmitter. (RCS-50) Size... 67 x 21 x 70 (73)mm / antenna °3 x 220mm Weight... 162g (with alkaline batteries) / antenna 3g Power supply... "006p" (6f22/6lr61) 9v battery x 1 Battery life... Approx. 62h (6lr61, continuous transmission) / approx. 1000h (stand-by mode, no transmission) Available channels... Uhf-a, uhf-b Mic effective range... 15m from circle point. (RCS-50) Size... 42.5 x 21 x 112 (120) mm / rod antenna 20mm (shortened) - 460mm (extended) Weight... 162g (with alkaline batteries) / antenna 3g Power supply... "006p" (6f22/6lr61) 9v battery x 1 Battery life... Approx. 11h (6lr61, continuous transmission) Controlling rcs-50... Keep pressing button 5 seconds to turn on rcs-50. Same procedure to turn it off. Rcs-20t uses vhf frequency for remote control.