Equilibrium Field Relief Max Fly Mask in Black. The Field Relief Mask Fly Mask offers excellent protection from flies and the sun from the tips of the ears to the end of the muzzle. The Max Fly Mask is made from super soft mesh that is comfortable for the horse and features a rigid central panel that allows clearance for the eyes and eyelashes. The Max Fly Mask features a detachable nose piece that allows the mask to be tailored to fit the individual horse and also allows the nose piece to be detached completely if necessary. Read more… The Mask offers excellent visibility and blocks 80% of UV Rays. Voted 'Best In Test' by Horse & Rider magazine. The second image demonstrates the Award and not the mask colour.