18650 to 20700/21700 Battery Adapter by AnalogDan 3d model
Cybrillion 21700 18650 Adapter - The Golden Greek Store
Generic 18650 To 21700 Battery Adapter For Astrolux FT01 / FT02 / FT03 LED Flashlight DIY 18650 Adaptor Holder: Buy Online at Best Price in UAE - Amazon.ae
18650 Battery Adapter For 20700 / 21700 Mods - iVapour
X-ADVENTURER CH-7 18650 26650 21700 Li-ion Battery USB Charger
new items on banggood: FT03 adapter (18650->21700) / Fitorch 26350 cell + P25 extention tube (26350->26650) - M4D M4XM4D M4X