The crystal shield is a defensive structure of the GDI in Tiberian Twilight.
The shield is capable of withstanding prolonged heavy attack... excellent for protecting key areas from harm. In an emergency, it can also stasis all units inside the shield, making them invunerable, but unable to act.
When built, the Crystal Shield always projects a blue energy shield around itself and nearby units and structures. The shield can absorb large amounts of damage, but both friendly and enemy units can pass through it. It can create a stasis field inside its shield similar to the Basilisk's, rendering all units inside immobile and invulnerable for its duration. While it is a strong shield, a prolonged attack will bring it offline. The shield slowly charges, and if the attack is stopped it will be able to bring itself back online. The Crystal shield's opposite number is the Nod Disruption Tower , which features a similar shield and the ability to stealth itself and all units inside its shield. An achievement if the player ues it to absorb lots of damage.