amsahr Replacement Battery for Dell 3721, Inspiron: 14(3421), 14R(5421), 14R(5437), 15(3521), 15R(5521), 15R(5537), 17(3721), 17(3737), 17R(5721) (4 Cell, 36WH) - Includes Cleaning Cloth Includes Soft Nonporous Microfiber Cleaning Cloth and ONE Compatible Laptop Battery 18 Months Manufacturer Warranty, 100% Compatible Non-OEM : Lithium Ion (Li- ion) Long Life Battery: Rechargeable with No Memory Effect and Power Surge Protection. 40WH, 14.8 Volts & 4 Cell Protective Retail Packaging, Each Product is Sealed with Anti-Static Shield Sleeve. Exclusive Offering of High Performance, Long Lasting, and Durable Grade A Cell Battery