Auto Turret (D20 Modern Equipment)
From D&D Wiki
When this is activated (a standard action), it transforms into a turret that floats about three feet from the ground and fills one 5 ft. square. The Auto Turret cannot move and cannot be used by any creature or character. The Auto Turret automatically fires one shot each round at all creatures and characters that are not allied to the creature or character that activated it within 80 ft. of the turret. The auto turret has an attack bonus of +5, deals 2d8 damage, and has a range increment of 30ft. The auto turret can be destroyed: it has a hardness of 8, 30 hit points, and an AC of 10. The turret can be deactivated by the creature or character that activated it, or by one of his allies. In this case, it folds up to original size and can be reactivated as normal.
An auto turret has a purchase DC of 40, with a restriction of Mil (+3), and weighs 10lbs.