KIMAX buret with a filling tube and overflow tube at the top of the buret that accepts 1/4 inch I.D. flexible tubing. Filling is through stopcock. Buret is self-zeroing style. Stopcock for all sizes is 2. Scale is durable black ceramic enamel. Designed from ASTM Specification E287, Class B requirements. Replacement stopcock is 41530F-2.