... supports hot-swap; PNP(plug and play) and automatic recognition.2,Supports WIN98/2000/XP2003/VISTA/7/2008 operating system.3 ... ,*,#,A,B,C,DFSK Modulate Mode: Logical 0:2200Hz±1%Telephone line Status Judge Voltage: 50-90AV(Ring), 18-48V(hook-off ... (Power off)Lightning protection level: 4Related models: GXUSB-2R 2-channel Telephone Call Recorder GXUSB-2R+ 2-channel Recording/dialing/playing prompt Box