Perch Cleanroom Vinyl ChairOur cleanroom chairs are covered in vinyl on the bottom as well. Filters are also added to the chairs to keep particulates from entering the chair from the air, which makes it a proper cleanroom chair. Meets stringent Cleanroom standards. The ergonomically contoured waterfall seat was designed to improve circulation and comfort. Weve seen other chairs fall apart almost out of the box. Bad welds, cheap casters, poor cylinders theyll do your chair in