Myler Dee with Hooks with Stainless Steel Correctional Low Ported Barrel 5 1/2" MB 27PBMyler Stainless Steel 3 3 4" Dee with Hooks, MB 27PB Correctional Low Ported Barrel, Level 2 3 The MB 27PB is a Myler correctional mouthpiece, which is a ported mouthpiece that collapses onto the outer lip and bars and rotates onto the tongue. The port, although narrow and somewhat low, allows room for the horses tongue to pass under the bit. When the reins are engaged and the mouthpiece rotates onto the tongue, it applies two concentrated points of