The Dynamic RS Single Joint Loose Ring Bit is by Herm Sprenger. It gives soft, but effective instructions for even better communication between horse and rider. The curved 16mm Aurigan® mouthpiece with an angled center joint lies perfectly in the mouth. 70mm stainless steel rings.
The Herm Sprenger Flex Control Loose Ring Bit is ideal for sensitive horses. This bit has an Aurigan® mouthpiece with a single joint and soft and flexible rubber over the center joint that protects tender spots in the mouth. Mouthpiece is 18mm and stainless steel rings are 70mm.
Questions regarding bit selection, jaw anatomy and proper bit fit according to the Herm Sprenger philosophy are discussed in this 90-page paperback by Brigitte Schulte & Heinz Baumann.