The compact Cobra Lapel Speaker/Microphone with a screw-in connector is compatible with these Cobra handheld marine radios*: MR HH150, MR HH350, MR HH500, MR HH600. An included adapter cable allows use with Cobra Walkie Talkies. Features an earphone jack for private listening (earphone not included).* Also compatible with legacy marine radio models: MR HH100, MR HH125, MR HH325, MR HH330, MR HH425, MR HH450, and MR HH475.• Clear audio projection in noisy environments• Function buttons are easy to operate even with gloved hands Function buttons are easy to operate even with gloved hands Earphone jack for private listening (earphone not included) | Lapel Speaker / Mic Accessory for Handheld Marine and Two-Way Radios