- With a shock absorbing, water repellent EVA lining, which absorbs energy from overreaching and protects the vital areas of the hoof. The boot is equipped with a tough rear strike guard, a strong Velcro closure and a no-turn knob to prevent the boot from spinning. Size S: Pony. Front and hind legs. Size M: Cob. Front and hind legs. Size L: Full. Front and hind legs. Size XL: Extra full. Front and hind legs.