Just wanted to throw this out there. The iHybrid clone one might find on fasttech only takes 18350 batteries but if you have a VamoV2 ( I can't comment on the other Vamos) then you have the bottom extension piece that the cap screws on to. That extension screws right into the bottom of the Chybrid and the chybrid button fits into the extension letting you use an 18650 battery in it.