This compact Boyle’s law apparatus provides a simple and convenient way to demonstrate the relationship between pressure and volume of gas.Mounted on a durable base, the apparatus consists of 30mm diameter graduated cylinder with a thumbscrew lever at the top and a piston inside. As the lever is turned, it pushes down the piston inside, reducing the volume of air inside the cylinder whilst increasing the pressure. The increase in pressure is registered on a bourdon gauge, which is connected to the cylinder. The bourdon gauge measures in psi and kilopascals (kPa or 105Pa), with the needle set at atmospheric pressure.Also included is an integral digital thermometer, which registers the temperature (requires 1.5 v AA battery). Overall height of apparatus is approx. 21cm.