What’s the inside diameter of the body? Do 21700 or 20700 fit?
The vast majority of the time that a flashlight says it will accept an 18650, it will not fit a 20700 or 21700.
No they don’t. It’s around 19mm
Bad luck… 
The body of a Convoy BD04 is wide enough to hold a 20700 and perhaps a 21700.
But…. because the battery goes in a cradle it doesn’t fit
Such is life. Lighten up! 
Hey guys, Sofirn is working on both a new light in the style of the L6/S70s as well as a new UI.
If you have suggestions on the UI or want to voice your opinion on what is currently suggested, check out this thread.
I just received my sofrin c8.f I have two other sofrin torches ,I have the SP32A the SP33A and now the new 8f .I have been to lazy to check the specs on my old fashioned light box ,but ehat I am impressed about these these budget light is the quality of maching qnd hig quality of anodizing and the extra steps done ,such as soldering the + and-s battery inputs dare I say the quality is on par of convoy and astrolux? I will do my best to do a review ,my .main block for me is using a host site to post pictures