Bought this to test launch our bottle rockets for science olympiad. The rocket/bottle launch is actually very impressive and almost surprising in its effect. Highly recommend an adult be present as it does lift off with a good amount of force.

Twist while pushing is the best way to get the bottle on without dislodging the ring. Vaseline is helpful to extend the life of the gasket. Plumbers grease (o ring lube) on the connection for the 2 liter bottle worked great!

It’s remarkably well built and thoughtfully engineered. Simple, easy to follow instructions made with durable materials.

The build quality of this unit is diabolical. Never worked. What a pile of effing garbage.

The only way to get it off is to pry it off with some type of lever. This makes staying safely away from it impossible and pulling the cord pointless. The launch tube is not flat and smooth and had odd bumps in it which caused leaks.

Water pours out the back in between pumps until the bottle is empty. No longer allows air to be pumped in. The product says that the optimal psi is set at 50.