The deadline to screen cargo on passenger planes in the US was August 1, 2010, well before the Dec 3, 2012 international deadline, so much of the equipment deployed to the domestic market is probably over 3 years old. However, the Itemiser DX and Ionscan 500DT, which do not expire, were in the mix as they were unveiled in 2009 and 2008 respectively. Does anyone know what is considered the useful life for these units?