Cwell Equine boots are generally available in three different sizes: S, M and L. To choose the right size it is necessary to measure the circumference of the front cannon bone. Take a tape measure and wrap it around the middle of the cannon bone without strengthening too much, then take the measure. If the measure is between 17 and 20 centimetres (6.5 to 9 inches), the right size of the boot is S. If the measure is between 20 and 23 centimeters (9 to 10 inches), the size is M. Over 23 cm (over 10 inches) the size is L. Even if we are buying protections for the hind legs, normally the measurement is taken on the front limb. It is in fact very uncommon that between front and rear legs there is such a difference to require boots of different sizes. But if we have doubts, we can always ask our shop for a couple of protections to try. Warning! Many people think that the protection must cover the entire deep flexor tendon even up to the carpus (the knee). Not only the part of the tendon most exposed to trauma is the lowest, but a protection that is too high would just bother the tendon when flexing, particularly during the jump.