This mask has been specifically designed to overcome the general weakness in the market, where most masks only cover the top of the nose and allow flies to continue to get underneath. Our mask fits over the horse's head and ears, nose and chin. It is heavy duty and will withstand 24 hrs reasonable use.It has an 8" x 4" velcro fastening strap, which will adjust to the size you need. We have kept it off-white in colour for night use and to reflect sunlight which reduces UV value by as much as 75%. It has a padded soft mink nose and face edging to prevent any soreness and rubbing. Has very good vision. Extra full size ( 17h and over ). Please state if requiredthis will be at no extra cost.