Whoa!
Having made these things years ago with a squeezy bottle and cork, I wasn't expecting too much, but my son was keen. Wow, this thing flies! Using a 1 litre drink bottle 1/4 full, we easily achieved 150ft. The wind then carried it about 70 yards away. Fortunately, we were in a field. It is well made, with turned brass fittings and a clever design which screws directly onto the bottle, using the latter's thread. The fins are detachable, which means they can come off in, for example, a tree. I might glue them on.
Using a track pump, it lets go at about 40 psi, then accelerates VERY fast: it says "not a toy" on the box for a reason. Also, it comes down with quite a thump: greenhouses beware!
Overall, fantastic fun. Just take care where you launch it...
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