Features: The transparent air duct uses the air to transmit the sound very original and clear. The air duct is easy to conceal, and the air duct transmits signals to reduce noise. It has a good feel when used with U94PTT and the operation of large PTT is convenient. Bracket-type throat vibration noise reduction earphones, avant-garde engineering design, easy to shrink and wear, the size of the coil can be adjusted, and the size can be adjusted according to the adaptation of the neck. The throat vibration emits sound, and it is highly noise-proof even when used in a very noisy and harsh environment. The surrounding noise, including wind, will not be heard. It is suitable for half helmet, full helmet, and also suitable for wearing a mask and ventilator. Applicable scenes: jungle, field battle, outdoor riding. U94 PTT part adopts high-intensity PTT, which can be pressed continuously for 30,000 to 50,000 times. The wire is made of cold-resistant PU tensile wire, which has high flexibility and strong toughness. The speaker adopts 32Ω±15% @1KHZ imported from Taiwan, the sound is loud and thick. Specifications: Material:Copper+PVC Sound Pressure Level 108±3dB@1KHZ 1mW Rated Power: 50mW Max Power:100mW Speaker Impedance: 32Ω±15% @1KHZ Mic Sensitivity: -31±5dB@1kHz 0dB=1V/0.316G Mic Output impedance 1200Ω±15% @1KHZ Adaptation model:ForHytera HYT PD600, PD602, PD602G, PD605, PD660, PD662, PD662G, PD665, PD680, PD682, PD682G, PD685, X1e, X1p Package Includes: 1x Air Acoustic Tube Earpiece note: Please allow 1-2cm errors due to manual measurement,pls make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.