Tether Trap is a Defensive Ability employed by Northstar and Northstar Prime. It takes the form of a mine that is deployed from the Titan that, when triggered, will tie a captured enemy Titan or Reaper down for a few seconds.
The Mine itself can, however, be destroyed by weapons fire, and a Ronin can use his Phase Dash to escape the trap. The Twin Traps Kit, available to Northstar, modifies the launcher so that two traps are fired rather than one, meaning that destroying the trap to free a prisoner takes longer.
The Aegis upgrade Explosive Traps, available at rank 1, will alter the traps so that upon being destroyed, they will explode and deal some damage to anything caught in the blast AOE. The rank 4 upgrade Trap Mastery will give Northstar two charges of the Tether Trap, so that two (or four, if the Twin Traps kit is equipped) traps can be active simultaneously.