... )FSK and DTMF single 2)free calling recorder sys 1 line USB phone call recorder box,recording all incoming and outgoing call ... descriptionThe 1 lines recorder box is strong recording funtion,including inbound number, exhale number, ... by YX Co.,LTD,with FSK and DTMF.And the recorder support compressed format,just like 64kbs,8kbs.It is benefit ...