Designed with input from some of the world's largest consumers of upright vacuums, the CV series are truly in a class by themselves. Uncompromising TRUE HEPA filtration is present in the high efficiency three stage filter system. The units come standard with this demanding level of filtration and were designed specifically to meet or exceed most worldwide indoor air quality standards. The CV 30 and 38 has incorporated the best ideas the industry has to offer and then improved upon them. All CV's come standard with soft rubber bumpers, on board tools, a protected hose and cord assembly, a simple to use height adjustment and specially engineered shock absorbing wheels.