This is an audio adaptor suitable for using on Motorola DP3400, DP3401,DP3600, DP3601, etc. The unit enables you to use an earpiece or headset which has a Motorola 2 pin plug fitted on the above radios. Remember, do not over tighten the securing screw otherwise you risk snapping it off in the radio body, finger tight is fine. Comes with integral dust cover to keep dirt out when not in use.