The Power Cable for the Alpha 100 allows you to plug your handheld into a cigarette lighter power receptacle in your vehicle. The Alpha is then powered from your vehicle's battery and save the rechargeable battery in your handheld. To this cable you are able to attach the split adaptor cable and charge both the Alpha 100 Handheld and the Alpha TT10 Collar unit from this one splitter. When running the handheld from the power cable it simultaneously charges the battery in the handheld!