The Astatic 202R microphones are miniature, high performance electret condenser microphones designed for low-profile mounting in panels, tables, or ceilings. They have been redesigned with improved RF immunity to greatly reduce susceptibility to radio interference from GSM based cell phones, PDA/cell phones, cell phones with walkie-talkie capability and other similar devices. They are excellent choices for teleconferencing, voice-lift, professional recording, courtrooms, surveillance and many other critical applications. The microphone is 1.1" in diameter at the largest point and mounts in a 13/16" opening in panels up to 2" thick. The 202Rs mics are extremely rugged and feature a solid machined brass body and Astatic Flex-FormTM hardened grille screens. It also has a built-in 80Hz, 12dB/octave high pass filter and are terminated with standard male 3-pin XLR connectors. Color-matched shockmount isolators are also included with each microphone. (15/16" mounting hole