Paso Curb Bit
Paso curb bits that are handmade in Columbia, South America, are the most common bits used worldwide to ride Paso Fino horses (and the Columbian diagonal Paso horse breeds). The Paso curb bit is a special kind of bit that evolved from those brought to America by the Spanish Conquistadors during the 15th century. The main difference between the Paso curb bit and the other curbs is the presence of some joints that reduce the bit’s severity.
Information from Science and Art of the Paso Fino Horse by Diego Bravo.