Fully-adjustable and designed to fit snugly. The throat knot should touch the horse"s throat latch, and ropes from that knot to the crown should come up behind the jaw bone. 1/4" Diameter rope. Sizes: Small Mini (27" - 29") - Poll: 8", Cheek: 6", Nose: 5 1/2" Medium Mini (30" - 32") - Poll: 10", Cheek: 8", Nose: 5 1/2" Large Mini (33" - 35") - Poll: 15", Cheek: 8", Nose: 6" Measure from where the noseband should rest (just below the jawbone), up behind the ears, and back down to the same point on the other side