Electric and electronic controllers used to operate ventilation installations, heat exchangers, air inlet installations, exhaust installations, heat pumps and heat recovery installations; temperature indicators; temperature sensors; temperature controlling apparatus; electric transformers and switches; electronic instruments for analysing air quality; hygrometers; voltage regulators; timers; technical measuring, signalling and checking apparatus and instruments used in ventilation systems wit...

window ventilators; namely, adjustable air vents for use in window frames to allow for air circulation