A film made for OLC (a training and development fund for the Plumbers, Fitters and Central Heating Industry) about the imposing technical installations in the Amsterdam ArenA. Caretaker Michiel Romeyn shows the latest trends in installations to a camera crew from NOS TV. Using for instance the grass heating, the waterpressure booster and the air filters, we finally reach the roof of the ArenA, where the caretaker proudly talks about the drainage system.