Comment by markus_zhang

My hunch is that IL intelligence bought some 3,000 - 4,000 pagers of the same models, fixed them with explosives and trigger systems, and swapped them with the package sent to Hez in the middle of transport or (probably) in the Lebanon distribution center.

So they needed to know: which company manufactured those pagers; which models are sent to Hez; when they were in transport and arrived at the distribution center; which packages went to Hez operatives, and much more information.

BTW rumors says the pagers were manufactured by a Taiwanese company, not confirmed though but some of my friends were able to read from the pictures that show what was left of the pagers.