The product is quite accurate. It's China (Amazon) and it came with no instruction manual, just setup by the numbers. The product info said go to their store on Amazon and send message for usage instructions. DEAD END!!! PPFD is accurate showed me quite a bit about my lights, intensity etc. You can log extensively. Shows separate red, green, blue light. Great for adjusting individual intensities. Okay so here is my issue and I hope someone else is using and can help:

Currently my lights are set (in flower) at 84% Red, 99% White (green) and 40% Blue. PAR is 800, DLI 36.

Are the readings for each band the actual range or do they just represent a percentage of light intensity at plant height? Guesses okay!