Ultralast 6V 100mAh Replace A544, PX28A, and 4LR44
10Pack 4LR44 A544 4G13 PX28A L1325 6V Batteries For Dog Training Shock Collars | eBay
Duracell PX28A at B&E Electronics
Amazon.com: LiCB 10 Pack 4LR44 6V Battery PX28A 476A A544 K28A L1325 Battery 6V Alkaline Batteries for Dog Collars : Health & Household
Vinnic L1325, RFA-18, A28PX, 4LR44, A544, PX28A, 4G13 6V Alkaline Battery for Dog Collars and Barking Control Systems - GN Batteries & Electronics Inc.