This paper model is a Trip Mine, one of the equipment items introduced in video game Halo 3, the papercraft was created by Ben Aerens. A Trip Mine can detonate in several different ways. If someone comes within its motion-sensitive range, it will detonate.
It will also detonate from being hit by bullets or from explosions. Although the Trip Mine has a larger blast radius than any of the grenades, it is not able to kill anyone with fully charged shields. It also normally cannot destroy a vehicle, or kill anyone within it unless they are already damaged. Because of this, it is usually best to use it as a way to harm numerous people with its large blast radius before finishing them off with a second weapon.
Also, throwing a Fragmentation Grenade or a Plasma Grenade onto it as an enemy walks by is a common way to successfully use the Trip Mine. The Trip Mine is only found by default in the multiplayer on the maps Sandtrap, Avalanche, and Rat's Nest. [Source: neoseeker]