Browning Invector-DS choke tube, flush-fit Full constriction (.035″, 75–80% pattern) for 12 gauge shotguns — the tightest standard pattern for long-range shooting. Longer than most flush tubes, with a differential banded gas seal and integrated spring suspension that keep powder residue out of the threads so it installs and removes easily and stays cleaner. Nickel chrome moly steel with a chrome finish. Fits only Browning shotguns marked Invector-DS (such as the Citori 725 and newer A5); not interchangeable with Invector-Plus or Standard Invector. Rated for lead shot only. UPC 023614373452.