Emisar Noctigon Replacement Tailcap Tail Caps D4/D4V2/D1/D1K/D4K/D4SV2/KR4

Perfectly fits

Just makes sure you get the correct size. Almost accidentally ordered 21700 tube.

It's a tailcap

Literally an original Emisar tailcap. Does what it's supposed to do. 5/5

jackson's the best

So helpful in solving any problems I have with lighting. Love this guy.