High efficiency particulate air filter (HEPA) refers to a filter which removes particles in the air by forcing it through screens containing microscopic pores.

Heat treatment solution is pertaining to a treatment in which an alloy is heated to a suitable temperature and held at this temperature for a sufficient length of time to allow a desired constituent to enter into solid solution, followed by rapid cooling to hold the constituent in solution.

Heat shrink (heatshrink or heat-shrink) is referring to a material used to connect two pieces of conductor together.

Hubble telescope is described as the largest orbiting telescope built. It sends back pictures and is extremely important to deep space research.

Humidifier is identified as either a free standing unit or a component of a central heating/cooling system that adds moisture to the air before it is distributed throughout the house.

Homogenous products is identified as products that are similar in quality, but different in price and require comparisons.

High capacity aircraft is described as a kind of aircraft which is equivalent to wide-bodied aircraft. These aircrafts are referring to: B747, B767, B777, A300, A310, A330, A340, DC10, MD-11, L-1011, IL-86 and IL-96.