HOKE Sampling Cylinders are designed and manufactured to stringent U.S. Department of Transportation (DOT) specifications to provide long performance life and maximum safety to the user. These cylinders are fabricated from seamless tubing or pipe with an increased wall thickness in the threaded area, which prevents expansion when valves are installed. Completely formed ends maximize strength and eliminate potential leak paths. Internal sandblasting removes surface imperfections and removes foreign particles. Single- and double-ended cylinders are available as standard in a variety of capacities from 10 milliliters to 4 gallons.