Manufactured to the highest standards by Wolfgang Muller Glas Technik. Standard Glas Technik Features: Wall Thickness - 0.01mm Overall Length - 80mm Drawn from clear, fresh and properly cleaned glass; Funnel at one end, sealed at the other; Supplied in non-confusing, color coded glass packages containing 25 tubes; Individual tubes are easily removed from glass package without fumbling and searching through the container. Exclusively distributed in North America since 1972 by the Charles Supper Co. Over 50 sizes are available from our inventory for immediate shipment. Special tubes will be quoted upon your request and specification.