AV-JEFE AVL623 Cocoa/Caramel / Brown Color Professional Mini Sweat Resistant Headset Microphone for Audio-Technica Wireless Systems. New Ergonomic, Flexible Frame, Easily Adjust to Fit Clear Voice Pick-Up. Great for Speech & Lecture. Ergonomic & Lightweight. Flexible Frame. Sweat Resistant Design. Compatible with Audio-Technica Transmitters: ATW-T1801, ATW-T27, ATW-T31, ATW-T51, ATW-T201, ATW-T210, ATW-T210a, ATW-T310, ATW-T310b for use with 200 Series, 1100 Series, 1400 Series, 1800 Series, 2000 Series, 2000A Series, 3000 Series, 3000A Series Not for Training / Fitness Class Use. Unique Slim Gooseneck Boom for Easy Mic Positioning. Boom Length: 4.5 inches (Sit by user's cheek). * "NOT" compatible with: ATW-T35, ATW-T75, ESW-T211, ATW-T601, ATW-T701, AEW-T1000, AEW-T1000a, ATW-T1001 for use with 600 Series, 700 Series, 1000 Series, 1200 Series, 4000 Series, 5000 Series, 7000 Series, System 10, System 10 Pro.*; ** Important: For wireless receivers & transmitters of other brands, please contact us to check the compatibility first, even their connectors look identical. **