Got some Envi bricks for free from the local stove store.....Not endorsing them...just stating what I have witnessed....They burn well in my stove....been mixing with wood....not sayin I like them better than good seasoned wood but if you are out of wood and have some cash and jonesin to burn....they burn well...no smell (like I have read here that other bricks like this do)....and the burn time is very long....just an FYI...never burned any of the other bricks of this sort before....so can't compare...