Our state of the art Asus W5F compatible notebook battery is designed and manufactured under strict European ISO 9001 standards. It meets and exceeds high priced OEM products, allowing you to power your computer with a superior quality battery for a fraction of the price! We stand behind our products by offering a one-year full warranty.CompatibilitiesASUS W5F, W5Fm, 70-NHA2B1000, 90-NA12B1000, 90-NHA2B1000, A31-W5F.