Replacement battery for WT-XXXX-HL1. Specifications: 28000mAh, 3.6V, Li-SOCl2. Compatible with: WT-XXXX-HL1, WT-XXXX-HL2, C1D1 Oleumtech Transmitters. Replaces: OleumTech SX1000-BP3. OleumTech replacement battery designed for Equipment/Survey/Test Charger devices. A direct drop-in replacement for the original battery.