Made in the usa, these chokes are for the browning invector plus shotguns.Steel, lead, & hevi-shot may be used in this constriction, however, no steel shot larger than #bb or speeds exceeding 1550 fps should be used in choke tube tighter than full.It is constructed from 17-4 heat treated stainless steel.Gauge: 12 GaugeConstriction Type: ModifiedConfiguration: Invector PlusFinish: StainlessChokes Included: 1Material: Stainless Steel