The Pelham has attachments for two reins, one near the mouthpiece and one at the end of the shank. These reins have similar action to the curb and bradoon reins in the double bridle.
The Polo Pelham 55 has 55mm shanks and utilizes a heavier cheekpeices than the standard Pelham.
The Polo Pelham 55 is supplied with curb hooks and chain.
The Waterford bit has many smooth flexible bumps or bubbles, which spreads the pressure over many points making it a light mouthpiece. The greater flexibility discourages a horse from leaning on it.
The Waterford bit is a good choice for a horse that leans, it also promotes mouthing and salivation. The Waterford is usually worn ¼" - ½" longer than your traditional mouthpiece in order to curl around the lips and maximise the effect.