High-Efficiency Particulate Air is a standard of air filter. By this standard an air filter must remove 99.97% of all particles greater than 0.3 micrometre from the air that passes through.
We consider a thinner chassis better because it makes the product more compact and portable. Thinness is a feature highlighted by many manufacturers of mobile devices, but it is essential for a wide range of products.
We consider a lower weight better because lighter devices are more comfortable to carry. A lower weight is also an advantage for home appliances, as it makes transportation easier, and for many other types of products.
The height represents the vertical dimension of the product. We consider a smaller height better because it assures easy maneuverability.
The width represents the horizontal dimension of the product. We consider a smaller width better because it assures easy maneuverability.