Emisar 21700!!!

Noctigon K1 with SBT-90.2 can use FET turbo, while other emitters can only use regulated mode up to 5A or 7.5A max current.

SBT-90.2 has a much bigger hotspot, but because it can put out more lumens it also has very good throw. Other emitters have very good throw, but the hotspot is much smaller.

I recommend SBT-90.2 if you can afford it.