WP products feature foam rubber gaskets and boots, sealed connections, gel-filled butt connectors, as well as urethane or thermal plastic potted circuit boards with internally sealed, field-adjustable trim pots and DIP switches for easy on-site programming Self diagnostic reports via email (testing com, mic, speaker, and switch) Automatic polling and programming software included SIP compatible (see page 2 for list of compatible IP-PBX phone systems) PoE powered (class 1, <4 watts) Automatic Noise Canceling (ANC) for operation in noisy environments VoIP eliminates the need for Push to Talk mode Network downloadable firmware Meets ADA requirements for Emergency Phones: Automatically lights the Call Connected LED Transmits a location I.D. or voice announcement Grade 2 Braille label for the visually impaired Non-volatile digital voice announcer with 28 seconds of voice memory Handsfree operation Marine grade 316 stainless steel prevents faceplate / push button corrosion Dials up to 5 emergency numbers E-1600BLT2IPEWP and E-1600AST2IPEWP can also dial up to 5 additional non-emergency INFO numbers Cycles through backup phone numbers on busy or no-answer