Meco makes the original. If you get one with an actual T6 it’s a decent light for the price.
I have one several years old and I grab it when I need a light that is ok to destroy or lose.
With the springs bypassed it makes about 900 lumens, comparable to the Zuesray zoomie that was popular a few years ago. Worst part is the switch.
If you are going to get one, get this one, it has real cree emitter (xml t6) most of the other ones have latticebright. MECO XM-L T6 1600LM 5 Modi Zoomable LED Taschenlampen 1x18650 Sale - Banggood Deutschland sold out-arrival notice-arrival notice
If they’ve mangled the driver since I bought mine you can always wire it direct drive.