noun
fireworks piece; set piece
Refers to a single firework or a constructed fireworks display piece, as opposed to the overall event or a simple firecracker.
夏祭りで大きな仕掛け花火が打ち上げられた。
A large fireworks piece was launched at the summer festival.
花火 is the general term for fireworks as a whole or the event; 仕掛け花火 specifically refers to an individual constructed piece or set piece.
Compound of 仕掛け (mechanism, device) and 花火 (fireworks), literally 'mechanism fireworks', referring to a constructed fireworks piece.