A Timer clamp is a specifically designed device used to hold the "petals" of a Xenomorph egg shut to insure the creature can't escape during transportation and will automatically fall off when its timer expires without anyone needing to be near the egg when it activates.
Overview
When unfolded, the prongs of the clamp are placed over the 'X' in the egg's surface. Spikes will then shoot out from each side of the extensions and bury themselves on either side of each slit, digging deep and holding like prehensile teeth; ready to be born or not, the egg cannot hatch until the proper code is punched into the clamp's miniature keypad or until its motion sensor activates.
Appearances
Gallery
Clamp depicted in Aliens: Music of the Spears.
Clamp holding egg shut in Music of the Spears.
Clamp holding egg shut in Music of the Spears.
Clamp being manually removed in Music of the Spears.
Timer clamps depicted in Aliens: Stronghold.
Timer clamps as seen in Stronghold.
Timer clamp being carefully removed in Aliens: Havoc.