1.7mL Posi-Lock™ Graduated Microcentrifuge tubes feature a large easy-to-open/close cap with the assurance of an audible "click" to know that your sample is secure. Frosted Large Cap and writing panel allows for an extra writing room and is resistant to smearing. Boilproof available Fits all standard 1.5mL centrifuge rotors, racks, and storage boxes Graduated every 100µL for easy volume identification Ultra-clear resin makes visualizing samples easy. Rated to 20,000xG Autoclavable Certified free of RNase, DNase, DNA, PCR inhibitors, and tested pyrogen-free. Made in the USA