4MWater Rocket Kit, DIY Science Space Stem Toys, For Boys & Girls Ages 8+

This was a lot of fun even though I only got to use it a couple times. Very easy to use. It goes pretty high. I would recommend doing it in the park though or open space rather than in the neighborhood lol some kids find it very fun other kids don't like putting into work because technology nowadays 🙄 but if you got a bike anyways there are automatic battery air pumps so that might be even more fun for kids because it's pure enjoyment versus any work

Very fun for all ages - adults liked playing with it as much as the kids. Works great. "A good time that was had by all".Comes with- 2 rubber cork plugs- 2 sets of 3 fins (and a spare fin for each set, tho they seem pretty durable, no breaks yet)- 2 plastic air tubes to connect tire pump to rubber cork in water bottle.- 4 small plastic connectors for connecting tire pump to the rubber cork via clear plastic tube(basically, one connector thru rubber cork, connect clear tube, another connector for bike pump; 2 sets)Minimal assembly:Insert tire pump connector thru the rubber cork provided so it sticks out thru wider part of rubber cork (only goes 1 way, cant mess it up)Connect clear plastic tube to connector on rubber cork, and insert other small connector into the other end of the clear tube to connect to tire pump (basically, 1 connector for each end of clear tube).Fill water bottle 1/3 full with water.Press the rubber cork into bottom of bottle. Press HARD.The harder you press it in, the more pressure is needed to pop it out and the higher it will go.Stand rocket up on fins as its launch pad.Start pumping the bike tire pump until the cork pops out and the rocket launches.(While reading about these bottle rockets, I could never figure out what the release mechanism was to actually launch the rocket - turns out its a function of how tightly you insert the rubber cork, thats it).We were launching 200-300 feet in the air once we figured out we just need to push the rubber cork in harder.While you can use any 1 liter bottle, I prefer the Seagrams Tonic 1 liter bottle - cuz then I have an excuse to make Gin & Tonics too! However, the Polar brand Tonic bottle is more streamlined, looks more like a rocket.And you can cut the top off another bottle to attach it on top of the main engine bottle for a bigger rocket, and a more streamlined look. (pointed nose vs flat bottom of main bottle on top) Google around and you will see examples.

My son wanted a "rocket set" for his 5th birthday, but couldn't really explain what he meant, so research led me to this. I've got a few cautions about it and I'll get to those, but there's plenty of great stuff about this toy.1) We can consistently launch this rocket about 4 stories high. It makes a great rocket sound and takes off like, well, a rocket. It's a blast, a huge performer. You know how you worry that things won't be as cool in practice as advertized? This is way cooler! Very exciting every time.2) Scientific method. We've been forming hypothesizes about whether more or less water would make it go higher and then discussing how to measure and what environmental factors (wind) might impact the results. Got the brain working while we're having fun.3) I can't imagine a toy being better at helping to make new friends. Every time we launch it up at our play ground, all of the kids and some of the parents get involved, ask questions, want to have a turn. We form launch teams, recovery teams, fueling teams, etc. Our boy has met some kids this way who are in his Kindergarten class that starts this week. He'll start school with a few friends in his class because of this toy. Can't really ask for more than that in a toy!Now a few tweaks and warnings:I am a road cyclist. Road bikes have smaller valve stems than regular bikes and things like wheelbarrows and cars. So, I happen to have pumps for both standards, but assumed that this was designed for the standard bike pump valve. The valve that comes with the rocket is too small to get a seal with the standard pump, but we get a better one with my road bike pump (Presta valve). The rocket launches by building up pressure from the pump and the water, so this is pretty important.With the presta pump, some air still leaks out. I have one kid hold the joint when we launch, but we still loose a little air that way. It's working for us, but this could be better implemented. I may work to modify ours at some point. I'm sure even with a standard pump, you could get this to work, but it might take some tweaking.All in all and amazing fun, safe and sneakly educational toy that has brought kids together and formed new friendships...all for $20. Can't beat it.