GADMEI Ultra-thin 2500mAh Card Shape USB Power Bank Portable External Battery Pack Material: Plastic housing Super Lithium-ion chip, cooling tech, energy saving technology and various protection system offers high safety coefficient Card design, smaller and lighter than normal power banks, easy to carry Battery Type: Rechargeable Lithium-ion battery Size: 62 x 96 x 6.6mm / 2.44 x 3.77 x 0.25inch