I bought this kit about twenty years ago when I was homeschooling my kids, and never used it.  The box is dented and worn.  The kit contains a booklet about Galileo's theories and discoveries and materials to make a telescope and thermometer, plus four marbles of different sizes to replicate some of his experiments.  Most of the parts are in sealed packages--only the marble package is unsealed.  It appears that all of the parts are present, except possibly the "experiment sheets," which are are missing if they are not part of the booklet.  (The booklet does describe several experiments, but I'm not sure whether that is what the box means by "experiment sheets.")

Please ask any questions before buying.