We bought these rockets for our son's 9th birthday party, and he and his friends had a fantastic time. It took a bit of time to put the insides together and cut and attach the fins before the children decorated them, but it was all clearly explained in the instructions, and the result was ten robust and exciting rockets which we launched repeatedly (and to great joy) in the local park! The Model Rocket Shop staff were also extremely patient in helping us to find all the right parts to buy, and even advising us on how to alter the rockets to account for launching on a windy day - brilliant all round!