Kit Kat is a type of fountain / show / “flower pot / shower” style firecracker (i.e. emits sparks upward like a fountain) in many listings.
Type: Fountain / Show / Decorative Cracker (not a bomb or loud single-sound type) — intended for visual sparkle effects.
Intensity: Likely medium to low — suitable for gardens, parties, nighttime visuals.
Target market: Children / general festive use, included among “Children’s Fancy Crackers” in some catalogs.
Variants: There seem to be stronger variants like “BIM BOM Bada Kit Kat” (i.e., larger / more powerful version) in the listings.