Moisture Control Tubing IDK Series SMC's IDK series is a moisture control tube. Condensation in a pneumatic system will cause operating failure and affect the life of pneumatic equipment. The IDK prevents condensation in small cylinders, air grippers, and air operated valves by diffusing water vapor in the piping to the outside before it is condensed. Features and Benefits • Prevents condensation • Made from fluoropolymer • Suitable for use with KQ2 and KJ fittings • Transparent Product Application Information Suitable for use with small cylinders, air operated valves and air grippers.