. Works like new! This purifier features a 5 stage filtration process. Washable prefilter and UV light . It has gas and dust sensors and a remote control. Different speed settings or automatic. This purifier is effective at controlling SMOKE, dust, odours etc in rooms up to 1500 square feet. Has been used minimally in non smoking, no pet home during allergy season. We have upgraded to a heat pump with air purification system built in so we no longer need it.