Clear Glass BOD Bottles come with glass stoppers and a white write-on marking space. Perfect for general BOD applications. Black Plastic-Coated BOD Bottles are perfect for light-sensitive BOD applications. Bottles include ground glass stopper, opaque cap, and foam insert. The black coating blocks out light rays from 400 to 800 nm. Use a bottle rack for storing and transporting your BOD bottles. Racks are corrosion resistant and plastisol coated (order separately).