Z-4190 bubble shield

The Bubble Shield is an anti-artillery and personal defense device developed by the UNSC's ONI branch. .

Overview
The Bubble Shield projects a transparent, slightly yellow tinted defensive sphere. The shield itself is similar to a Geodesic dome, made of tessellating hexagons. The shield protects against bullets, lasers, flames, and other projectiles used primarily by the Marine forces of the UNSC and The Covenant. Vehicles and players however, are still able to pass through it. After a significant amount of time has passed or if the shield generator has taken enough damage, it will collapse. Covenant Loyalists, mainly the Brutes have been known to secure human weapons and equipment for their own ends, the bubble shield being one of the most common.

Development
The Bubble Shield was created by the Office of Naval Intelligence. However it is not known if it was created using UNSC technology or if it was reverse engineered from Covenant technology similar to the way MJOLNIR Mark V energy shields were created.

Deployment
Despite being UNSC technology, UNSC Marines rarely deploy it during the campaign, while Brutes deploy it often. At least one or two brutes in a covenant battle squad always have a bubble shield on hand. Brutes generally activate their bubble shields immediately following aerial insertion and when in large numbers.

Trivia

 * In an early Halo 3 build the bubble shield was able to roll like the Power Drain.
 * This shield resembles the description of the Onyx Sentinel shields in the Eric Nylund novel Ghosts of Onyx.
 * With no Damage modifiers, a melee with most weapons will destroy the shield generator.
 * It is confused to be a Brute weapon, since Brutes always activate these devices, however it was developed by UNSC (possibly from brute technology)
 * If you deploy it and throw a spike grenade into it, it creates the "Bubble of Death".