Phoropter Dust Cover in Black. 100% durable nylon phoropter dust covers are used for covering phoropters or refractors to protect against dust and the environment. Unique and professional looking black color to hide grease and dirt stains. These dust covers fit most types of phoropters; including AO, Reichert, Topcon, B&L, and Marco refractors. The dust covers are made with a longer zipper track at the opening to make sure that most dust and dirt will not enter the bag, making those required cleanings less frequent. Size of dust covers are 19" x 13".