Safely conduct lab experiments involving vacuum and air pressure with our microscale bell jar and vacuum set. Expand a marshmallow, balloon or shaving cream. Show that liquids boil at reduced pressure. Learn by experimentation that air has mass. Perform an experiment to actually calculate the density of air. This apparatus will help increase students’ understanding of air pressure and vacuum. Instruction and experiment booklet included. Bell jar diameter 7 cm; height 8.5 cm.