The Colin Miles Butterfly Flip from Bombers Bits has a sweet iron mouthpiece and 55mm centre piece with rings. This creates tongue pressure if the horse becomes strong and also gives the horse something to play with, which encourages a soft contact and helps to keep the horse's attention on the bit.
The blue sweet iron mouthpiece encourages salivation, softening and acceptance of the bit because it oxidises easily, creating a warm, sweet taste in the horse's mouth. The double joint means the mouthpiece follows the contours of the horse's mouth, which reduces the 'nutcracker' action associated with single jointed bits, and resultant bar and palate pressure.
The Butterfly Flip cheekpieces are formed in a D-shape, with the hooks offering three different rein positions to vary the amount of poll pressure and leverage exerted. The reins can be moved around the bit rings to give varying degrees of control.
Please note that the blue will fade with use.