These are bare PCBs designed to take 9 superflux LEDs or 5mm/3mm LEDs. They are fibreglass board, not cheap phenolic resin, and have a printed overlay (may be black or white ink) and are tinned. They measure around 35mm square.
The LEDs are configured as three strings of three LEDs, and the boards will take either 0.4 watt mini resistors, or standard quarter watt sized resistors if you stand them on end.
These are ideal for my various superflux LEDs and are a cheap way to make small, bright light modules.