Complete apparatus consists of a 500ml boiling flask with thermowel, distilling column, condenser and a 200ml product receiver graduated in 2ml subdivisions.Component parts are held together with 35/25 ball & socket joints except the top of the distilling column, which is a 19/38 outer joint. Supplied without clamps. Used in the determination, at reduced pressures, of the boiling temperature ranges of petroleum products which decompose when distilled at atmospheric pressure.