Straws are 5.25" in length and generally used for freezing and insemination. Manufactured of PVC plastic and have a wick and powder plug at one end. Gamma Irradicated. The wick and powder plug at one end creates a fluid barrier and prevents leakage but is also designed to act as a plunger, forcing the contents out in front of it when used with an A.I. gun or E.T. gun. Gamma irradiation may result in minor discoloration of the straw.