Quick, simple, and accurate tool for measuring a horse's mouth for a properly fitting bit. Molded from durable engineered resins Fully washable 1/4" increments Full directions included. Put the Bit Sizer in the horse's mouth at the corners where the bit would sit. Place the stop against the horse's cheek. Wait for the horse to hold the Bit Sizer if he is chewing. Hold the stick on the opposite side directly at the corner of the horse's mouth. Carefully bring the stick out the front of the horse's mouth without letting go of the stick. Read the measurement at the placement of your fingers. This is the size of your horse's mouth which correlates to the size of most of the bit mouthpieces he needs. "Please send me a 4.50" bit in exchange for this 3.75" bit. Glad I bought that bit measuring stick!" - Suzanne
