TVs that contain Red Shield display an icon depicting a red sphere with a bright center. The Red Shield itself take the form of a pulsating red sphere.
In the gameplay of Sonic 3D Blast, when picking up the Red Shield, Sonic will get enveloped by the Red Shield. While wearing it, Sonic will be protected from a single hit that would otherwise inflict normal damage. It also makes him immune to fire-based hazards, such as the lava flooring in Volcano Valley Zone. Once damage is taken, Sonic will lose the Red Shield and suffer knockback without taking damage. However, it does not protect Sonic from dangers such as bottomless pits.
It is worth noting that the Flickies following Sonic also receive a small Red Shield when Sonic obtains one; the Flickies' Red Shields do not disappear upon taking damage unless Sonic also takes damage.