Capacity: 2.8Ah, 3.0Ah, 3.5Ah, 4.0Ah and 5.0Ah options to extend cleaning time. Compatible design: Designed for Cordzero models including A9, A902RM, A906SM and A927KGMS. Reliable performance: lithiumion technology delivers consistent power and longlasting performance for the vacuum cleaner. Easy to install: Userfriendly design makes battery replacement quick and easy. Use scenario: Extended cleaning sessions in large homes or multiroom layouts where longer run time reduces interruptions, with the 5.0Ah option providing the longest runtime. Use scenario: Busy households with pets or traffic areas that require sustained power across rooms, enabling a swift battery swap to maintain performance. Use scenario: Spare battery for rental properties or small offices using Cordzero vacuums to minimize downtime during cleaning tasks.