This is a kind of fine quality 21V rechargeable lithium battery, there are two different capacities for you to choose, you can choose according to your demands. There are two different capacities of 5pcs lithium battery cores or 10pcs lithium battery cores for you to choose, you can choose according to your demands. Built-in LED power indicator helps you get work done more easily, it's timely to recharge, help you monitor the battery charging status and check if the battery is in nice condition.

 
Specifications:
Name: 21V Replacement Battery
Nominal voltage: 21V
Battery type: 5pcs * 1500mAh lithium battery cores type, 10pcs * 1500mAh lithium battery cores type (optional)
Item size:
5pcs lithium battery cores type: 120 * 76 * 50mm / 4.72 * 2.99 * 1.97in
10pcs lithium battery cores type: 120 * 77 * 70mm / 4.72 * 3.03 * 2.76in
Power adapter: 87 * 50 * 69mm / 3.43 * 1.97 * 2.72in
Item weight:
5pcs lithium battery cores type + adapter: 388g / 0.86lb
10pcs lithium battery cores type + adapter: 634g / 1.40lb
Package size: 160 * 140 * 100mm / 6.30 * 5.51 * 3.94in
Package weight:
5pcs lithium battery cores type: 410g / 0.90lb
10pcs lithium battery cores type: 645g / 1.42lb

Packing List: 
1 * Replacement Li-ion Battery
1 * Battery Adapter