Coals last about 90 mins start to finish on a Votex bowl. Haven't tried with other style bowls, but works great with my Vortex. Price is best deal for the most amount of coals per box, good for stocking up for more consistent bowl sessions. Does not burn shisha but cooks very smooth and even works good with some type of foil cover(heat management) at beginning and end to make coals last for the longest time. 3 coals per sesh seems to be the right amount any more would just burn shisha instantly. Great deal to buy in bulk you never know who's down for good smoke sesh!!!