Teaching about pressure is usually a matter of locating the right rubber stopper, with the correct number of holes, to fit a flask of the proper diameter, to accommodate glass tubing cut to the desired length. No wonder experiments on pressure usually end up as teacher demonstrations! We eliminate the hassle and safety hazards with rubber tubing, canning jars, rings and lids. Students construct airtight and watertight systems that measure pressure, expand balloons, siphon and pump water and more.