This package is for the driver who is allowed to use a 2-way radio with a RACEceiver. The RACEceiver Ace has a built-in reverse splitter that allows you to route the audio from your 2-way radio through the RACEceiver Ace and use one earpiece. This package includes the RACEceiver Ace, Professional Driver Earpiece and a male-to-male adapter, holster, AAA battery and instructions. You may need an additional adapter depending on your 2-way radio.