Micro fittings for regulating air flow through standard airline tubing for devices such as air-stones, filters, protein skimmers, ornaments, etc. Also for low pressure liquid feed lines for metering pumps, fish display holding cubicles, fertilizing systems, calcium reactors, and drip irrigation of water gardens and paludariums. Threaded fittings can be used for attaching to PVC pipe walls to build manifolds for air or water feed. Available with barb x thread ends.