I have one that I use as a par meter. My research led me to the conclusion that its accurate enough to give you a good idea. If you're trying to get a really tight specific range because you've got finnicky sps it may or may not be good enough. If you want to know where your hot spots are and where you need more light its perfect. These are made up numbers for the sake of example but if you read a par value of 280 and its critical that it not be actually 290, maybe buy/rent a fancy meter. If 280/290 mean no difference to you then it works fine.