Kimble kimax ray-sorb burets ray-sorb burets are used in titrations containing light sensitive analytes. Funnel fill style buret less than 1% transmission below 400 nm and approximately 5% transmission from 400-600 nm supplied with a chemically-resistant, self-lubricating ptfe stopcock plug and a kim-kap dust cap replacement 2 mm straight bore stopcock plug is 821001-0002 easy-to-read durable opaque white ceramic enamel scale manufactured to the specifications found in astm e694 calibrated to the accuracy requirements found in astm specification e542 manufactured from 33 expansion, low extractable borosilicate glass conforming to usp type i and astm e438, type i, class a requirements and then ray-sorb processed. Warning: this product can expose you to chemicals including tetrafluoroethylene, which are known to the state of california to cause cancer. Prop 65 warning