Replacement battery for OP-5500. Specifications: 2000mAh, 3.6V, Ni-MH. Compatible with: OP-5500. Replaces: Midtronics 59873353, Midtronics BP-55, Midtronics HHR-15F3G1. Midtronics replacement battery designed for Equipment/Survey/Test Charger devices. Tested for reliability and long service life.