The Browning Invector-DS Pro (often referred to simply as the DS Extended or Signature series depending on regional cataloguing) is the premium, competition-tier extended choke variant of the Double Seal system.

While it retains the signature internal brass compression seal at its base to stop fouling from seizing the threads, the "Pro" extension adds distinct hardware advantages optimised for fast-paced sporting clays, skeet, and trap.

• Extended Internal Parallel Section: The Pro tube extends roughly 20mm past the muzzle crown. This extra length gives Browning engineers more physical runway to create a longer internal "parallel section." By flattening out the shot column more gradually before it exits the barrel, the Pro model minimises flyer pellets and delivers incredibly uniform, patch-free patterns.

• Aggressive Knurled / Fluted Band: The dark band extending beyond the muzzle features deep ergonomic fluting. This allows you to rapidly check tight anchoring, break the thread loose, or swap chokes mid-round using nothing but your fingers, completely eliminating the need to fish a choke wrench out of your vest pocket between clay stations.

• Muzzle Protection: Moving the point of ignition and pellet exit 20mm forward protects your shotgun's actual barrel crown from accidental dings against gravel, dynamic clay barriers, or the walls of a duck blind.

As seen on the bottom tip of the tube, the integrated brass sealing ring is what sets the DS platform apart. When torqued into place, this soft brass face creates a gas-tight seal against the internal barrel wall, completely isolating the threads from carbon build-up. Even after blasting through hundreds of targets at a weekend clay shoot, the choke will spin out effortlessly without binding.

The full, complete lineup of the factory Browning Invector-DS choke scaling matrix covers everything from the widest, most open spread up to specialised maximum tight restrictions:

• The Steel Shot Leap: Because steel pellets do not compress or deform like lead when squeezed through a barrel taper, shooting steel shot through an Invector-DS choke automatically jumps the pattern tightness up by two full tiers. For example, a factory Improved Cylinder tube will physically throw a Modified pattern when firing steel.

• The "Lead Only" Structural Boundary: Never fire steel shot through factory Improved Modified, Light Full, Full, or X-Full Turkey Invector-DS chokes. Because the walls of the DS system are precision-thinned to maintain a balanced, lightweight muzzle feel, the extreme pressure of unyielding steel shot can bulge the barrel tip or permanently lock the tube into the threads.

• Spotting From the Rim: When using standard flush-fit variants, you can easily identify what is loaded into the gun without a wrench, simply look directly at the exposed rim at the muzzle end to count the notches.

• Browning Invector-DS Shotgun Compatibility

  The Invector-DS (Double Seal) system is only compatible with modern, back-bored Browning shotguns (primarily 12-gauge and 20-gauge). It will not fit older models marked Invector or Invector-Plus.

  Shotgun Action Type	Compatible Browning Models
  Over-and-Under (O/U)	Citori 725 (All field & sporting variations) Citori 825 / B825 (Latest flagship platform) B725 (European market equivalent)
  Semi-Automatic	Modern A5 (Kinematic Drive models, including Wicked Wing & Sweet 16)