Shield Booster
Shield Boosters are an item found in Jedi Outcast and Jedi Academy singleplayer and multiplayer that restore a player's Shield amount.
There are two varieties: Small and Large. A small shield booster restores 25 shields, and a large shield booster restores 100 shields (50 in singleplayer). Due to restoring such a large number of shield points, the large shield booster will cause a players shield points to exceed 100. While a player's shield point number is over 100, the value will slowly count down to 100.
Note: a player's shield count cannot exceed 100 points in singleplayer. Some mods (such as Jedi Knight: Enhanced) circumvent this.
The official strategy guide for JK2 mentions a third shield booster type: a shield exchanger which swaps health for shield points. Curiously though, this shield booster type is not mentioned in either the code or levels, and the strategy guide doesn't list this type spawning anywhere.