HQRP Battery for Sportdog FieldTrainer 425, 425S, SD-425, SD-425S, FT-125, WetlandHunter 425CAMO, SD-425CAMO, FT-125W Remote Dog Training Transmitter Field-Trainer SAC54-13734 SDT00-13857 + Coaster HQRP&reg; Rechargeable Transmitter Battery plus HQRP&reg; Screwdriver and HQRP&reg;Coaster; Battery Voltage: 3.7V; Capacity: 200 mAh; Li-Pol; Compatible with Original Battery; 200 Days warranty!