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Myler® MBB Black Steel Flat Shank with Narrow Medium Ported Barrel MB 43MP

Colors/Options: Black Steel

Myler® MBB Black Steel Flat Shank with Narrow Medium Ported Barrel MB 43MP

Item #: X1-013723
Helpful Information
Our Guarantee

Myler® MBB Black Steel 6 3/4" Medium Shank, MB 43MP Narrow Medium Ported Barrel, Level 2-3. For Western disciplines. 

The MB 43MP does not rotate onto the tongue, but instead sits solidly across the bars and lips of the horse’s mouth. The port is narrower than a Level 3 mouthpiece, but still offers room for the horse’s tongue to pass under the bit. Because the port is narrow, when the reins are engaged, the horse will feel a slight pressure on the outside edges of the tongue as a reminder rather than a strong reprimand.

The port on this mouthpiece is 1 1/2" high, so it will apply little to no palate pressure. The MB 43MP is the mildest of the Level 2-3 mouthpieces in terms of tongue pressure, just one step below a Level 3 mouthpiece. Sweet Iron mouthpiece oxidizes and encourages salivation.

Key features:

  • Independent Side Movement™.
  • Sweet iron mouthpiece.
  • Curved mouthpiece does not pinch lips or bars.
  • Copper inlay.
  • Black shank will discolor over time to an antique brown.
  • Stainless steel dots.


  • For more tongue pressure, see the MB 27LP. For more tongue relief, see the MB 41PB.
  • For slightly less tongue relief or a lower port, see the 43LP.
  • For the same benefits but with some palate pressure, see the MB 43HP.
  • For the correctional version of this mouthpiece, see the MB 47 and MB 47PB.
  • For the Level 3 version of this mouthpiece without Independent Side Movement, see the MB 12 or MB 98.

The MBB shank is a length of flat black steel curved slightly back towards the horse, with a teardrop purchase and a rein ring. The mouthpiece has a fixed attachment to the cheek with a decorative stack. The shank is decorated with stainless steel dots. The purchase is angled slightly away from the cheek to avoid rubbing. The black steel will discolor over time to an antique brown.

The MBB flat shank is an indirect (curb) rein action designed to be used with a curb strap which attaches to the purchase. This shank uses the combination of fixed cheek and fixed rein to apply pressure to the mouth, chin and poll.

Action: indirect.

Degree of leverage: moderate.