These batteries have a shorter charging time and longer service life. Batteries do not have a “memory effect” so the phones can be charged at any user-friendly time. Charge faster - use longer - feel safer! Features:The battery is protected against overcharging, overheating and ignition.Optimally selected discharge parameters maximize battery capacity. Compatible mobile phone models:Samsung Galaxy S21.Samsung Galaxy SM-G991B.Samsung Galaxy SM-G991. Samsung Galaxy SM-G991U1.Samsung Galaxy SM-G991B/DS. Note: the list of compatible batteries and smartphones may be not complete. In case of doubt, always ask a consultant for advice. Compatible part numbers:EB-BG991ABY.GH82-24537A. Specifications:Capacity: 4000 mAh.Type: Li-ion. Voltage: 3.88 V. Warranty: 12 months. Important information! Waste batteries and accumulators must be disposed of into specially marked containers.