Pyrotechnical sausages? (7)
I believe the answer is:
bangers
'sausages?' is the definition.
(banger can mean a sausage)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for bangers that I've seen before include "Crates" , "explosives?" , "Loud fireworks" , "Sausages" .)