Midas grade choke tubes use the long taper technology of invector-plus, but produce tighter patterns.It extends beyond the barrel for easy removal and installation, no wrench necessary.It uses minimum gap geometry plus a high resolution "rms" finish to reduce buildup of plastics in the shotgun bore.These tubes are stainless steel with a black oxide finish and a laser-etched gold accent band.When used in browning barrels, the barrels must be threaded for invector-plus.Approved: Steel,Lead,Non-ToxType: ExtendedGauge: 12 GaugeConstriction Type: CylinderConfiguration: Invector PlusFinish: Black OxideConstrictiondiameter: .000Chokes Included: 1Recommended For: 20 ydsMaterial: 17-4 Stainless SteelPorted: No