As the camera zooms it, the object is revealed to be a detonator for an explosive device.
They were held after a rifle, two handguns, ammunition and a bomb detonator were discovered at a house Lurgan, Co Armagh.
Known by railroad men simply as a torpedo, this is a small detonator fastened to the rail and set off by a locomotive's passing wheels.
He had separated the fuse and the detonator from the plastic explosive.
Audible signals are principally the locomotive whistle and the detonator (torpedo).
It is understood a detonator on the device went off but the main package did not explode.
The suicide jacket is essentially a bomb kit worn as a waistcoat next to the skin, fashioned from canvas and with plastic explosives and a detonator secreted in four pockets.
The group has access to at least small stocks of artillery ammunition, detonators , and explosives.
You need plastic explosives, detonators , volunteers and somewhere to groom your potential martyrs and build your bomb.
Fake explosives, detonators and real guns were taken undetected on to a British Airways flight between Manchester and Gatwick on Friday in a security test.