Nitecore 21700 3.6 V, 4000 mAh Lithium-ion Protected Battery (NL2140)
Buy XTAR X4 Protected 21700 Battery Charger 18650 Charger LCD Display AC and USB Input Port with Wall charger 2A Fast Charger USB Output for Rechargeable 3.6V 3.7V Li-ion 1.2V Ni-MH Ni-CD
Dual NiteCore 21700 Li-Ion Batteries Kit NL2150HP
Buy XTAR X4 Protected 21700 Battery Charger 18650 Charger LCD Display AC and USB Input Port with Wall charger 2A Fast Charger USB Output for Rechargeable 3.6V 3.7V Li-ion 1.2V Ni-MH Ni-CD
20700/21700 battery case
Keeppower Type-C USB Rechargeable Li-ion Battery Button Top Protected – UKWELL