Eggbutt bit from Bombers.

The eggbutt prevents the horse from being pinched at the lips/corners of the mouth by the bit rings and provides a more stable feel against the horse. The eggbutt keeps the bit steady in the horse's mouth.
The Ported Barrel was created to reduce pressure on the tongue with the help of the medium-high port, which creates more space for the tongue. The pressure on the bars is reduced by distributing the pressure over a larger area and preventing the nutcracker effect.