Pinout obtained from Chatterbox USA for the helmet-side connector of the Noise Reducing stereo headset as used on the Chatterbox FRS X2 and GMRS X1 radios.
| Pin Number |
Pin Name |
Description |
| 1 | - Spk | Speaker Ground |
| 2 | + Mic | Microphone Positive |
| 3 | + R.Spk | Right Speaker Positive |
| 4 | - Mic | Microphone Negative |
| 5 | + L.Spk | Left Speaker Positive |
| 6 | N/C | No Connection |

