Landmine

Were you also looking for the Brute Land Mine or the Trip Mine from Halo 3? A Landmine is a stationary explosive that is set to appear in Halo: Reach. Landmines may be placed in Forge Mode, and in Race, they’re an integral and multifaceted part of the overall experience. It functions similar to that of the trip mine, a usable equipment in Halo 3. Its only known appearance thus far is in Multiplayer.

Trivia

 * Landmines can be activated by proximity. If you drive close enough to one, they will explode after a short delay. This can be used to stop any player following close behind you.
 * As seen on pictures, they look more powerful than the Halo 3 tripmine, which didn't kill when the player when they had full shield (with normal player damage).