The Quick Release adapters allows the microphone to disconnect from the radio without disconnecting the adapter from the radio. Cost effective solution when changing radio manufacturers. EPC-EP523 for Motorola Multi-Pin Radio Models: XTS 1500, 2500, 3000, 5000, MT1500, MT2000, MTS2000, MTX8000, MTX838, MTX9000, MTX-LS, JT1000, HT1000, GP900, PR1500. EPC-EP534 For Motorola Multi-Pin Radio Models: XPR6300, XPR6350, XPR6500, APX6000, APX7000.