Investor-ds choke tubes, a revolution in choke design. The double seal keeps tubes Cleaner. Longer choke tapers are optimized to percentages, not dimension only. The next generation choke tube. Fit flush with the end of the barrel but are longer than competitors' tubes. Proprietary differential banded gas seal eliminates residue build up and makes chokes easy to remove and install. Features:- integrated spring suspension holds the seal tight. Specifications: - material: nickel chrome moly- pockets: chrome- choke gauge: 16- choke pattern percentage: 75%-80%- choke notches: I- weight: .16 oz