Guardian壁挂式电话机SCR-11-V-H Guardian壁挂式电话机型号SCR-41-V-H Guardian Telephone电话机SCT-40-V-H   IP Features  •  PoE 802.3af enabled (Power-over-Ethernet) or    alternate power source  •  Compatible with most SIP-based IP-PBX servers     that comply with SIP RFC 3261  •  Network web management  •  Guardian Discovery Utility makes it easy to     detect, locate and launch the web based     configuration screens  •  Product self diagnostic testing available through     web interface  •  Network adjustable earpiece volume and     microphone sensitivity  •  Network downloadable firmware  •  Remote programming – allows you to manage     your network from a central location    Product Features •  Weather and dust proof metal keypad •  Armored handset cord  •  Heavy duty G type industrial volume control     handset  •  16 gauge corrosion protected steel enclosure     with powder coat finish  •  Rust and corrosion resistant stainless steel     hardware  •  Electret noise reducing microphone  •  Electronic ringer for reliability  •  Service temperature range -22° to +140°F    ( -30° to +60°C )  •  Weather, dust & corrosion resistant for any     industrial application  •  Magnetic reed hook switch to reduce parts     subject to wear  •  Modular parts for easy service  •  Hearing aid compatible •  1/2” NPT Conduit hub