The U.S government rigorously tests the pens it uses

The U.S government rigorously tests the pens it buys. The pens must be assembled by blind people and should be able to write for a mile at temperatures from 160 to -40 degrees Fahrenheit. They are designed to fit undetected into uniforms and should stand in for a two inch fuse. These pens can also be used for an emergency tracheotomy.