Pop this on the top of an 18650 battery to allow it to be used within a device that takes a 21700 battery.
Related Products
21700 Fenix Battery - 5000 mAh
Fenix ARB-L21-5000 V2 is a Premium Quality High Capacity 21700, 5000mAh Lithium - ion battery from F..
£26.99 Ex Tax: £22.49
21700 KeepPower Battery - 5500 mAh
These high-capacity KeepPower 21700 battery cells work well for caving lighting, featuring all the e..
£14.99 Ex Tax: £12.49
18650 KeepPower Battery - 3800 mAh
These high-capacity KeepPower 18650 battery cells work well for caving lighting, featuring all the e..
£12.99 Ex Tax: £10.83
18650 Fenix Battery - 4000 mAh
Fenix ARB-L18-4000 is a Premium Quality High Capacity 18650, 4000mAh Lithium - ion battery from Feni..
£26.99 Ex Tax: £22.49