Very similar in construction to device #2. Same 'Rcandy' propellant.
Fused with the newer meal-IO twisted paper fuses.
Containment failure.
Fuse burnt deathly fast, about 1.5 seconds before grain ignited. Containment failure was almost immediate. The CATO barely lifted the rocket off the launch stand, but the grain bounced a few times as it burnt in the sand.