Retevis Listen Only Earpiece 3.5mm receiver listen only earpiece. The earpiece can compatible with two way radios radio speaker mics remote mics MP3 players and other audio accessories with 3.5mm jack. The length from the earpiece pin to the coil tube is 59in/15cm. The length from the transparent conduit interface to the coil tube is 9.06in/23cm. The original length of the coil tube is 5.51in/14cm. The maximum length of the coil tube is 51.18 in/130cm. Interface with Clip The listen only earpiece has a clip design at the catheter interface, which is convenient for fixing the wire. And the catheter part is detachable, which is convenient for cleaning the transparent catheter part. Durable Cable The listen only earpiece cable is sturdy and durable. Not easy to knot and not easy to break. Effectively extend the life of the headset. with 1 Pin 3.5mm The listen only earpiece's pin is 1 pin 3.5mm. It can compatible with radio speaker mics remote mics two way radios MP3 players and other audio accessories with 3.5mm jack. Compatible with the following devices: Fits radios or speakers Mic with 3.5mm jack, MP3 players and similar devices with 3.5mm connector, but listen only. Package included: 4 x Retevis 1 Pin Surveillance Headset