Replacement battery fits 5 Drummond Scientific compatible models. Specifications: 700mAh, 3.6V, Ni-MH. Compatible with: Portable Pipet-Aid XL, Portable Pipet-Aid XP2, Portable Pipet-Aid PK, Pipet-Aid XL, 4-000-36. Replaces: Drummond Scientific 4-000-036. Drummond Scientific replacement battery designed for Medical devices. Dependable performance you can count on.