Featuring a rubber base, velcro closure headpiece and clip throat lash for easy fitting and to keep the muzzle in place. Dengie, performed a scientific study to see how much our grazing muzzle restricted their horses' intake. The study showed a 75% to 86% reduction of intake. Keep in mind that this was a short term study and the horses hadn't worn muzzles before. The longer a horse wears a muzzle the better he/she gets at working it and she/he will get more grass.