This rechargeable battery Li-ion from Coast (XP11R, TX11R, HP7R) 3,7V 4Ah is efficient and is made of high-quality material. This batt 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.