ENGENIUS DuraFon1X Single-Line Industrial Cordless Phone System with 2-Way RadioDuraFon 1X system 1 line, long range, industrial phone system 2 way radio 12 floor in building penetration 250,000 sq ft of facility coverage 3,000 acres of property, open land coverage Features multiple handsets, up to 9 per base unit Works behind any analog port PBX, VoIP, PSTN, FXS or POTS Rugged & durable design for industrial environments Features 6 hours talk time & 50 hours standby time Li Ion battery pack AC charging cradle with power adapter