This rechargeable battery Li-ion USB from Coast (RL10, FL, HL45, PM210, PM450) 3,7V 1000mAh and is made of high-quality material. This batt is efficient and is friendly for the environment. Coast is praised all over the world for its excellent price-quality ratio. Unprecedented performance and a 5-year warranty are the foundation of the success of this American brand that has existed for more than 100 years.