Introducing the concept of pressure, for comparing pressures, for gas-compression experiments and for demonstrating overpressure and underpressure. Two precision glass syringes of different volumes with ground piston and weight pans on stand. Includes 15 disc weights on a storage rod for adding to plunger. Connection between the syringe hoses via a tubing clamp, safety catch for the smaller piston. Volume of syringes: 10 ml and 50 ml Ratio of piston cross-sections: 10:3 Ratio of piston masses with weight pans: 10:3 Mass of weights: approx. 400 mN each Base plate dimensions: approx. 140x100 mm²