The SARSTEDT 500 Pieces Centrifuge Polystyrene Tubes are high-quality lab supplies perfect for medical and research applications. These 5ml tubes feature a screw cap for secure sealing and are made of durable polystyrene material. With a total of 500 pieces included, these tubes are ideal for centrifuge operations and provide a reliable option for storing and transporting samples in a laboratory setting. Made in the United States by the trusted brand SARSTEDT, these tubes are a must-have for any healthcare or research institution.