We are manufacturer, professional microphones. 1, Goose neck 2, -47dB+_2dB 3, Alone one or for PCS. 4, Passed ISO ,CE Certi We are manufacturer, professional microphones.1.Goose neck2. -47dB±2dB.3. Alone one for pcs.4. Passed ISO, CE, Certificate etc... Systems function: 1. Can connect 60 unit representatives. The every master systems, and unit Expansion can store 180PCS unit representative to ...