Replacement battery for X3. Specifications: 20 mAh, 3V, Lithium Vanadium Pentoxide. Compatible with: X3, X5, Z4. Replaces: Panasonic VL2020, Panasonic E39, Panasonic E46, Panasonic E52, Panasonic E60, Panasonic E81 and 6 more. BWM replacement battery designed for Car Key Remote devices. Delivers steady power for reliable everyday operation.