Permanent graduation line Machine-blown bodies Heavy-beaded, heavy-tubing necks are tooled for polyethylene stopper Stopper is made with a closed bottom and is of linear, high-density polyethylene to conform to Standard Taper stopper dimensions

Calibrated to Class A ASTM E-542 and E-288 Supplied with a certificate of identification Traceable to NIST standards The graduation line is sharp and permanent. Large white block letters make it easy to read. Supplied with a Standard Taper stopper.