For those who would like additional protection to the SIMPLE Boot, softee-leather-covered foam collar. Sold in pairs. Small - Fits boots sizes 0 - 2 Medium - Fits boots sizes 3 - 4 Large - Fits boots sizes 5 - 6Remember that there is a break in period required to soften the leather at the bulbs and around the collar of your horse's new boots. Like your own riding boots, it is recommended that time is taken to gradually break in boots. The first day should be worn for 20 - 30 minutes. The next day you can increase the time and so on. Horse's hooves, skin thickness, bulb sensitivity and conditioning can vary, so please monitor the wear and increase time in the boots as appropriate.