Trust Sweet Iron Dee Bit Jointed
The D-ring cheekpiece consists of two rings that are shaped like a D. As the rings cannot move back and forth, this cheekpiece offers more stability but also lets the rein aids come through more directly. The D-shape gives more side pressure (against the cheek), making steering easier.
A single-jointed mouthpiece has one joint, which puts less pressure on the tongue than a double or multi-jointed mouthpiece. This mouthpiece acts mainly on the layers and sides of the tongue. A single-jointed mouthpiece is considered a standard mouthpiece.