Rambo(R) Micklem(R) Bit Straps Rambo(R) Micklem(R) Multibridle Replacement Bit Straps for horses. Made from Eco-Friendly vegetable tanned leather with silver hardware. Sold as a Pair. Specifications: Sizing: Pony - 13.2HH and lower - under 27cm (10.6 inches) measurement Large Horse - 16.2HH and higher - 31cm to 33cm (11.4 to 12.2 inches) measurement Taking a measurement of your horses head will provide you with a more accurate guide to your horses' size requirements. To achieve this measure the distance from the bottom point of the protruding cheek bone on one side of the head, to the bottom point of the protruding cheek bone on the other side of the head, going over the nose.