I ordered these off 1688 via Superbuy. They should have 4 of the same dies that LHP531 (9) and LHP73B (16) are using. The specs look very promising and I'd expect them to be the most efficient and brightest 3535 emitters, although not particularly throwy.
Here's the official product page/datasheet: https://en.lumenpioneer.com/product/776.html
Mine are 5300K CCT bin, 550-590lm flux bin and 2.6-2.8V voltage bin. Overall the best possible bin listed in the datasheet.
I will try to find some time to solder them onto a PCB these days and try them in a light. I will also send some to koef3 for proper measurements as I lack tools to do so.
by the_ebastler
