【Compatible With】This walkie talkie earpiece compatible with Motorola 1 pin SL300 SL7550 SL7580 SL7590 SL4000 SL3500e SL1K SL1M talkabout etc. 2.5mm Single Pin C-Ring Two Way Radio Headset TLK100 SL300 Earpiece for Motorola SL7550 SL7550e SL3500e TLK 100 Walkie Talkie.
eBay