Replacement battery fits 8 EXFO compatible models. Specifications: 10000mAh, 3.7V, Li-Polymer. Compatible with: MAX-600, MAX-605, MAX-610, MAX-625, MAX-630G, MAX-635G and 2 more compatible models. Replaces: EXFO GP-2147, EXFO 01WQ0037-03. EXFO replacement battery designed for Equipment/Survey/Test Charger devices. Ensures your device stays powered through regular use.