MOBIL] 20 gauge Featherlite Competition Choke Tube used for。Amazon.com: Muller Chokes, LLC - [Optima HP 12 Gauge Featherlite。ALL WATERFOWL CHOKE TUBES - MC LLC。Muller Chokes: How Jimmy Muller Started The First Space-Age。ミューラーチョークx2、チョークレンチx1Ü1 = Skeet/Improved CylinderÜ2 = Light Modified/Modified