Made from high quality UV resistant materials, unmatched resistance to chemicals, algae growth and UV damage. It can be left out year-round, buried or on the surface, in any weather. Size: Outer Diameter (Approx.): 7mm, Internal Diameter (Approx.): 4mm, this size is better compatible with micro-drip irrigation system, to connect the adjustable emitters, drippers, sprinklers, etc. Compatible with most brands of 1/4" Barbed Fittings, Spot Watering Emitters, Micro-Bubblers, Misters and Sprays. It can handle up to 60 PSI and is not rated for constant pressure. Before assembling, please put the connected part of the tubing into hot water for 10 seconds. Flexible: industry leading flexibility allows tighter turns with fewer elbows for fast, easy installation in garden, flower bed, ground cover or other landscaped areas. Function: use as the main line in a small drip irrigation system or to branch off from larger 1/2" Drip tubing to micro-watering system. Perfect for small, narrow and tight planting areas, as well as areas with tight curves or many switchbacks., Manufacturer: UCLEVER