SC-43 Oring with Drop CurbThe Drop Curb is perfect the perfect bit when the typical O Ring isn't enough, This bit is a 2. 5" ring with a headstall ring, a setback curb, & a rein lock. This bit has more instant reaction compared to a typical o rings. It is similar to the 143, but without a noseband. The setback curb allows the horse to be introduced to curb pressure. This bit is a good for all levels of horses especially when doing slow work.