Upgrade your Dyson DC21 with this high-quality rechargeable battery pack. With a capacity of 21.6V, 4000mAh, and 86.4Wh, you can enjoy longer run times for your vacuum cleaning needs. This battery pack is compatible with Dyson DC21 and ensures a reliable and safe power source for your cleaning chores. Designed to provide maximum power and durability, this battery pack is perfect for those who demand high-performance from their vacuum cleaners. It is an open box BOTKK product that comes with all necessary components and instructions for easy installation. Invest in this battery pack today and experience the convenience of uninterrupted cleaning sessions.