These glass connecting tubes are straight and have a 6mm diameter constrictions on their ends so that rubber tubing can attach to them securely.
WARNING: This product can expose you to chemicals including arsenic, which are known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
Our products are not toys. Use in a laboratory or educational setting only. Not for children 13 and under.