PYREX® borosilicate glass, heavy duty, with screw cap.

Constructed of heavy wall glass for greater mechanical strength. Graduations are with durable white enamel. The 10 ml size is graduated upward from tip in 0.1 ml increments. The 40 ml size is graduated in 0.5 ml increments to 10 ml, and from 10 ml to 40 in 1 ml increments. Tubes are fitted with a phenolic screw cap.