Super Bum are the classic caps from Edison Giocattoli, the Italian maker that has been producing them for decades for toy guns that work with paper strips.
The blister holds ten strips of eight shots, eighty caps in all. You feed a strip into the magazine of the toy pistol; each pull of the trigger moves the strip on one place and sets off a cap. Nothing leaves the barrel - a cap gives only a bang and a puff of smoke.
Check before ordering which format your toy gun takes. This refill is made for guns that accept strips of eight shots, and does not fit models that need rings or loose caps.
Worth picking up a few at once: a strip is quickly used up, and a cap gun without caps loses half its charm.