yeah they usually snuff nuts. I have experimented with about 1k worth of them. Waste of time and money so far. The 660nm that should be used usually is not and the blues are sometimes off as well. Maybe a company will eventually get it right but so far its hype. CFL kicks the shit out of them imo, cost wise, plant response, heat. LED's also give off some heat for SURE.. any size relevant to plant growing at that. Any person who says different is full of shit.