Kraken Battery 18650 for Ringlight 1000 and Hydra 1000
21700 to 18650 battery adapter sleeve -- options? - #22 by BOO5TED - Rechargeable Batteries - BudgetLightForum.com
21700 to 18650 battery adapter sleeve -- options? - #22 by BOO5TED - Rechargeable Batteries - BudgetLightForum.com
Amazon.com: MINCHEN 6pcs 18650 Big Plastic Sleeves, Big Plastic Tube Holder for 18650 Battery, Battery Plastic Holder Converter for 18650 Battery to 26650 : Electronics