SIZES: I measured the length of the fronts of the masks (in front of the ears at the top of the mask to the bottom of the mask) to give buyers a better idea of size. Small: 8" in length Medium: 10" in length Large: 11" in length. Protects your horse's face and eyes against flies, dust, dirt, and debris! Protects your horse’s face and eyes from harmful UV rays. Aides in healing after eye injuries. See through mesh won’t obstruct your horse’s vision. Double latch closure, making it harder for other horses to pull it off.