Advanced Technology DHS0100 Heat Shield Halo 2 Shotgun Universal Aluminum 13.75" L The Halo 2 from Advanced Technology is a high strength steel heat shield that fits on most 12 gauge shotguns. This item will not fit on vent rib barrels and the barrel lug must be at least 13.75 inches away from the receiver. Type: Heat Shield Model: Shotgun Dimensions: 13.75" L Size: Universal Material: Steel Finish: Black