cashel crusader designer horse fly mask, freedom, yearling cashel the crusader fly mask is the comfortable, durable, safe ?y solution! made with soft, breathable nylon micromesh, our patented three hole cap design gives lots of room for your horse’s eyes, lashes, and temples without damaging the forelock. your horse will have a natural, complete ?eld of vision protected from sunburn and 70% of uv rays.