THE PHILADELPHIA GROUP-Amazing Science Kits: Solar Balloon. Fill this six-foot balloon up with air, let it sit in the sun, then watch it rise! Makes a great school science project. This kit contains (1) 6ft solar balloon, string, and an instruction sheet. Recommended for ages 8 and up. WARNING: CHOKING HAZARD-Small Parts. Not for children under 3 years. This set contains chemicals that may be harmful if misused. Adult supervision required.