2x Pack - Sennheiser IS 410 Battery - Replacement for Sennheiser BA300 Headphone Battery (150mAh, 3.7V, Lithium Polymer) Replacement Battery for Sennheiser BA300, Set 830-TV, RI 830, Set 830 S, RI 830 S, IS 410, RI 410, RS 4200, RR 4200 Battery Capacity: 150mAh, Voltage: 3.7, Type: Lithium Polymer Quantity: 2, Lifetime Warranty On Sale for a Limited Time! Grade A Quality. High Capacity.