It entered Austrian military and police service by 1982. Despite initial resistance from the market to accept a "plastic gun" due to durability and reliability concerns, and fears that the pistol would be "invisible" to metal detectors in airports, Glock pistols have become the company's most profitable line of products, commanding 65% of the market share of handguns for United States law enforcement agencies as well as supplying numerous national armed forces and security agencies worldwide. Glocks are also popular firearms amongst civilians for recreational/competition shooting, home/self defense and concealed/open carry.