I have a pair of boa boots that were recommended to me by the Farrier, size 2 fits either one of my horses. I do not have a issues with putting them on and I use the gaiters which are inserts that seem to help make the fit. I pratice putting them on the off with my horses so that if I am on a stony trail I can get them on fairly quick. I have a friend that uses the old mac and old mac only, however the gaiters are the same for each type of boot old mac/boa boot which in nice to know. The old mac have a more aggressive tread and are better in mud and wet grass although they seem to wear faster than the boa boot. They really help if your horse is like mind and gets stone brused, although we are going to try shoes next spring for the first time on each of my horses , one is 13 and other is 7 ( mother and daughter ) .