From Garry's Mod
Sets the collision bounds for the entity, which are used for triggers ( Entity:SetTrigger, ENTITY:Touch ), determining if rendering is necessary clientside, and collision ( If Entity:SetSolid set as SOLID_BBOX ).
The minimum vector of the bounds. The vector must be smaller than second argument on all axises.
The maximum vector of the bounds. The vector must be bigger than first argument on all axises.