The Buster Roller link in the middle is shortened to 40mm which increases bar and tongue pressure making the bit sharper than conventional link bits. The increased pressure on the bar will lift the head and the roller will increase pressure on the tongue bringing the chin in. Best suited for a horse with a low head carriage and which leans on the bit.
This bit is good for strong older horses.

The mouth piece is made from blue sweet iron, because it:

oxidizes easily
encourages salivation
helps bit acceptance
is warm and sweet

Please note the blue will fade with use.