These YATE solid fuel tablets are sized for hexamine-type folding stoves, sold six to a pack in a reusable PE tube that keeps them dry in a damp pack or tent vestibule. Each tablet weighs 8 g, 61 g for the full pack, so a handful cover a few nights of boiling water for tea or a dehydrated meal without carrying a gas canister.
Solid fuel burns slower and less hot than gas or liquid stoves and leaves a sooty residue on pots, so it suits emergency backup, ultralight minimalist trips, or short outings rather than someone cooking two hot meals a day. The tube can be refilled once the original tablets are used, so it is worth keeping even after the first pack runs out.