Graduated at 0.2, 0.4 and 0.6 ml. Flat tops and writing area on the side of the tube for labeling. Ultra tolerance for centrifugal forces of up to 20,000 RCF. All tubes offered with special low friction surface. "Popping" highly resistant during heating. Made in various standard colors. DNase / RNase free. Autoclavable. 1000 tubes in 1 pack.