AquaGuard Gravity Flow Eye Wash Refill, 8 oz, Bacteriostatic Additive ORS NASCO Excellent durability Six inch metal barrel Excellent durability Six inch metal barrel permanent marker is leak proof with a seamless metal body Heavy duty chisel felt tip with anchored nib construction Marks on wood Steel Metal Arbor Diam [Nom] 7 8 in Big Catalog NO Brand NORTON Catalog MPI Catalog Color Black Construction Catalog NO Country of Origin CN Dia Bacteriostatic additive refill Eyewash unit should be inspected regularly and water in unit should be changed at least once every six months One 8 oz bottle will preserve up to 20 gallons of potable water for up to six months