The unit is made of one piece of 22-gauge

accepts hand towels and waste through the opening

wet soap from sliding off the dish and onto the floor

and a cast wall flange with set screw

Alera True Hepa Air Purifier Replacement Filter, 1/Ea - ALEAPFILTER material-BMC (Reinforced Polymer) The unit is made ofTrue HEPA filter removes up to 99. 97% of microscopic airborne particles. Designed to fit Alera 4 speed HEPA Air Purifier. Replaceable HEPA filter lasts 720 hours. Easy to install. Design to fit the Alera 4 speed HEPA Air Purifier. This True HEPA filter removes up to 99. 97% of microscopic airborne particles. For optimal results, replace filter every 720 hours.