Sort of like the other guy that replied to you, but if you cherry it right; you can keep it going for a while, and with this type of blunt that has the metal screw inside of a glass pipe, you can twist the mouthpiece to push the ash out and have fresh burning herb. In theory you can light a glass blunt once and never have to again until it’s done. Although, it makes it much easier to put out and continue later than a pipe, and it’s better than a regular blunt due to the lack of tobacco or nicotine.
Same idea as a joint, a tube that holds weed you smoke. Instead of combustible paper its glass holding the flower. Experience-wise a little bit closer to smoking a pipe.