The compact drying tubes come filled with 30 grams of 10-20 mesh indicating Drierite desiccant (anhydrous calcium sulfate), ideal for drying air and gases in small scale laboratory applications. A rubber hose connection provides an immediate flow of dry gas. The tubes measure only 8" L x 3/4" OD (20.3 x 1.9 cm) and features inlet/outlet ports which accept tubing ¼” to 1/16” (0.635 x 0.15875 cm) ID and a 20-micron Porex® filter at both ends. Absorbs up to 3 g of moisture.