what is a gerb
Gerb (pyrotechnic) For other uses, see Gerb (disambiguation). A gerb is a type of firework which produces a jet of sparks, usually lasting between 15 and 60 seconds. It is a thick-walled tube filled with pyrotechnic composition and possessing a choke, which is a narrowing in the tube. Gerbs are often referred to as 'fountains'.