The hands-free weather resistant Sentinel is flush or surface mounted and designed to be fixed to a vertical surface by vandal resistant tamperproof screws. The combined metal keypad and stainless steel faceplate provide protection from the harshest environments up to IP65. Incoming calls are indicated by a flashing LED and audible warble tone. A volume control button is provided for noisy environments. Two pre-programmable memory location buttons are also included (MEM1 & MEM2).