Double Jointed Copper Roller Pro King Dee Bit

Like the blue steel version, this describes a mouthpiece material and design combination that can be built onto various cheek styles (loose-ring, D-ring, Full Cheek, or even a gag) — so the cheek/ring choice still determines the bit's lateral action, while these features shape the feel in the mouth itself.

Breaking down the features

• Polymer mouthpiece:
• Made from a synthetic "space age" polymer rather than metal — often scented (commonly apple) to encourage acceptance.
• Feels warmer and softer than metal against the tongue and bars, generally regarded as gentler and more forgiving, especially for horses that are apprehensive about metal bits or have sensitive mouths.
• Well accepted by most horses due to both the softer material and the palatable scent.
• Double-jointed construction:
• Consists of three parts — two outer sections plus a center link — rather than a single hinge.
• This reduces palate pressure and distributes contact more evenly across the tongue, bars, and corners of the mouth compared to a single-jointed mouthpiece, avoiding the sharper "nutcracker" action of a single joint.
• Allows greater mobility in the mouthpiece, which can improve comfort and reduce resistance in many horses.
• The size and shape of the center link influences how much tongue pressure is applied — a thicker center link means more tongue pressure, making mouthpiece choice somewhat adaptable to individual mouth conformation.
• Copper roller:
• A small rotating roller, usually pure copper (often 99.9%), set into the center of the mouthpiece.
• Copper is a soft, warm metal with a taste horses generally find pleasant, which encourages salivation and helps keep the mouth moist.
• The roller also gives the horse's tongue something to engage with, which can promote relaxation, softening, and a quieter, more settled mouth — while also giving restless or fidgety horses a constructive outlet.
• In some designs, the rolling action additionally discourages leaning on the bit, since a horse can't get a fixed, stable purchase against a moving roller.

What it's good for

• Horses that are apprehensive about metal or slow to accept a bit: The combination of a soft, palatable polymer mouthpiece and a pleasant-tasting copper roller is specifically aimed at improving comfort and acceptance.
• Horses with sensitive mouths or dislike of "cold" metal contact: The polymer's warmth and give can make the overall feel gentler than an all-metal mouthpiece.
• Horses that need encouragement to relax the jaw and salivate: Useful for tense, dry-mouthed, or resistant horses, similar in intent to sweet iron or copper metal bits.
• Horses that fidget, chew excessively, or seem to need something to do with their tongue: The roller offers a controlled, contained outlet for that tendency.
• Horses that lean on contact: The rolling action can discourage a horse from bracing against a fixed mouthpiece.
• Young or green horses learning to accept contact: Often used as an approachable, comfort-focused introduction to bit acceptance.

A note on classification

• As with the blue steel/brass roller combination, the overall severity and lateral action still depends on the cheek style the mouthpiece is built into — a loose-ring version will feel different from the same mouthpiece on a Full Cheek or gag bit, which would add steering support or leverage respectively.
• This mouthpiece and material combination is generally considered mild, prioritizing comfort, salivation, and acceptance rather than added control.

Summary

A double-jointed polymer mouthpiece with a copper roller combines a soft, warm, palatable material with an evenly-distributing double joint and a salivation-encouraging copper roller — making it one of the gentler, more comfort-focused mouthpiece options available, well suited to sensitive, apprehensive, tense, or fidgety horses that benefit from extra encouragement to relax and accept the bit, regardless of which cheek/ring style it's paired with.