Rocket and CO2 parts.

Puncture assembly and set screw to hold it in CO2 support tube.

Spring and CO2 jett.

The exit end of CO2 support tube and a nozzle.

The bottle cap has a 1/2" hole and the ram plug just fits snuggly into it.

In goes the CO2 jett and spring.

Then you press in the puncture assembly and put the set screw in through the slot in the support tube to hold everything together. Notice the screw slot allow the puncture assembly to move in about 1/4". this will puncture the CO2 jett seal when the rocket is dropped.

Stick the nozzle in and put the CO2 assembly in the (water filled) rocket.

Screw the cap on.

This is the front end of the rocket. It's hard to see, but the puncture assembly butts up to the top of the rocket.

Just push the ram plug in and now it's ready to go. When the ram plug hits the base of the launch guide, the bottle continues down and pushes the puncture assembly into the CO2 jett. The spring makes sure that puncture assembly is pulled back out of the jett. It seems to work very good. It kind of bounces off the guide base and then the thrust kicks in and it continues upward.