Replacement battery fits 6 Blaupunkt compatible models. Specifications: 900mAh, 3.7V, Li-ion. Compatible with: Flextone ECHO HD eR1, Callstel BFX-300, BT Drive Free 111, BT Drive Free 112, BT Drive Free 211, BT Drive Free 311. Replaces: Callstel TM533443 1S1P, Blaupunkt TM533443 1S1P. Blaupunkt replacement battery designed for Car Speaker devices. Provides reliable power for your device.