Compatible rick type repeater interface for mobile radio compatible models: cm300, cm200 cm series, (must use 2 cm series models.) Cdm750, cdm1250, cdm1550, (CDM series plug into the center 16 pin of the 20 pin jack) pm400 gm series gm300 series M series matric series radius series m1225 gm380, gm950, gm340, gm360, gm3188 sm50, sm120 features: connector: 16 pin plug length: approx. 15 " package included: repeater interface.