Stalion Strength 1430mAh Internal Replacement Li-Ion Polymer Battery for iPhone 4S Replacement Battery Model APN: 616-0579, 616-0580, 616-0581 for Apple iPhone 4s A1387 (AT&T, Verizon, Sprint), A1431 (International Versions). Battery Specs. Capacity: 1430mAh. Battery type: Lithium Ion, Voltage: 3.7V Li-ion. Duration: 5.25Wh Tools Set Sold Separately."TECHNICAL EXPERIENCE REQUIRED" Battery that is designed specifically for your Apple iPhone 4s (GSM & CDMA Versions). CE and ROHS certified. Replacement for over charged internal batteries or dying battery cells. Prolong your iPhone life with a Stalion replacement battery!