AVEC CHEM Respirator Voice Amplifier for gas mask – a voice amplifier dedicated to CM-6, OM 90, OM 2020 & TAPR half mask gas masks (or any device connected to a standard 3.5mm jack ). Connects to the TAPR Microphone system, in seconds and without modifications, then attaches to a MOLLE support, on a belt or directly on a jacket or vest.