"Accessory PBX Panasonic KX-NSM705W, 5-Channel SIP Extension Activation Key (5 SIP Extension) 5-Channel SIP Extension Activation Key (5 SIP Extension). For KX-NS500/1000 "
Accessory PBX Panasonic KX-NSM705W, 5-Channel SIP Extension Activation Key (5 SIP Extension) 5-Channel SIP Extension Activation Key (5 SIP Extension). For KX-NS500/1000