The two wire long acoustic airtube earpiece is one of our most popular designs and is perfect for covert surveillance where discreet communication is essential. The 2wire harness splits into two at the PTT/Mic enabling the user to conceal the cable underneath their clothing with the earpiece running up from the back of the collar/tshirt, etc. The speaker transducer gives exceptional audio output. The heavy duty PTT design coupled with the sensitive Electret condenser microphone makes this a perfect product for discreet communication in complex environments.