A Ring cheekpiece introduces poll pressure as well creating leverage on the mouthpiece, the 2½ Ring version is the softest version of ring bit as the ½ ring softens the leverage on the mouthpiece and poll.
The Elliptical is a 45 mm lozenge, it is stronger than the Control Plate due to it having a smaller surface area. Consequently, a horse using his tongue as a means of pushing against the bit and therefore taking control, will draw back and tuck his chin in, coming back to a better point of control.
The blue sweet iron mouthpiece oxidises easily, warms up quickly and tastes sweet in the horse's mouth, which encourages the horse to salivate and accept the bit without resistance.
Please note that the blue will fade with use.