ASI Qwik-Snap MicroTubes are made of premium polypropylene plastic allowing for a crystal clear tube and centrifugal strength. Available in 1.7 (graduated to 1.5ml), 2.0ml, & 0.6ml sizes, the 1.7ml and 0.6ml tubes are also available in assorted colors. They feature a secure-snap cap that ensures a strong seal and eliminates leakage and evaporation. The 0.6ml tubes are packaged in bags of 1000 and the 1.7ml & 2ml tubes come 500 per pack. Capable of withstanding boiling temperatures up to 121˚C and freezing down to -80˚C, the Qwik-Snap micro centrifuge tubes are the perfect choice for your research.