"Double Voice Cracker" Huppscustom

3 inch ID ( 4 1/2 OD) Double voice Cracker
AKA "Bouncing Betty"
Hand made American firework

These do not need a launch tube to fly in the air. Everything is self-contained. Set it on flat surface and run :-)
These use a small whistle fuse ( spolette) for timing. You hear a little of it just before the explosion.