Replacement Microphone for OEM model RMN4025. Has RJ-45 type connector and fits many models including: CDM1250, CDM1550, CDM1550LS, CDM1550LS+, CDM750, GM1280, GM140, GM160, GM300, GM338, GM340, GM360, GM380, GM398, GM640, GM660, MCX760, MCX780, PRO3100, PRO5100, PRO7100