A Knee Defender is a gadget designed to bring relief and irritation simultaneously during plane travel. The device allows one passenger to enjoy some extra space -- by preventing the no-doubt-annoyed passenger in the seat in front from reclining. 

The $22 plastic contraption consists of two wedge-like pieces with rubber grips that fasten to the seat tray. Once it's attached, the unfortunate person in the front cannot recline. The product comes with a courtesy card. It reads, according to The Mirror:

“I realize that this may be an inconvenience. If so, I hope you will complain to the airline. Maybe working together we can convince the airlines to provide enough space between rows so that people can recline their seats without banging into other passengers.”

Airplane Interior The FAA is considering the easing of restrictions on passengers using electronic devices during takeoffs and landings. Photo: Reuters

There wasn't much courtesy in evidence on United Airlines Flight 1462 last Sunday. The flight was headed from Newark to Denver, but the plane was diverted to Chicago’s O’Hare International Airport mid-flight after two passengers got in a squabble. One man used the Knee Defender and wouldn't remove it when asked by a flight attendant. The woman in the seat ahead of him tossed a cup of water at the man. Both passengers were taken off the plane in Chicago. 

After the incident made national news, the Knee Defender website crashed. The site maintains: "If the airlines will not protect people from being battered, crunched, and immobilized -- very real problems according to healthcare professionals, medical studies, government agencies, and even some airlines -- then people need options to protect themselves,” CNET.com reported. 

The gadget’s inventor spoke out after the altercation. "Sometimes people do things they shouldn't do on airplanes, but as far as I know this is the first time anything like this has happened" involving the Knee Defender, Ira Goldman, the man who created the contraption in 2003, told USA Today.

"United could make seats that do not recline, but they have not chosen to do so," Goldman said. "In the meantime, the Knee Defender says right on it: 'Be courteous. Do not hog space. Listen to the flight crew.' Apparently that is not what happened here."

Even though the Federal Aviation Administration has not banned Knee Defenders from airplanes, flight attendants will ask travelers to take them off since they “interfere with plane equipment,” The Mirror reported Tuesday.

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