This is definitely not a PAR meter, I ordered it because I don't trust the results, so I ordered an Apogee MQ-500 (the one with the updated Quantum Flux sensor which is also accurate for the LED spectrum ) and compared them. This meter didn't even read T5 fluorescent tubes correctly, both sensors side by side read: T5 fluorescent tubes: 175 PPFD with this meter, 230 PPFD with Apogee. I tested the 750W KIND LED X2 Commercial LEDs with both sensors at the same distance from the LEDs and also varied the spectrum. If KIND LED is installed on white LEDs only: 239 PPFD on this meter, 312 PPFD on Apogee. LEDs only: 431 PPFD on this meter, 542 PPFD on Apogee. KIND LED X2 with all LEDs at maximum (VEG setting): 857 PPFD on this meter, 1056 PPFD on Apogee. I really wanted this meter to work for me but unfortunately I believe it is a lux meter that has been converted to a display similar to the PPFD scale. It's too far away for me and I had to send it back.