The specially formulated polyethylene tubing is the key component to the system. This tubing is made of linear low density polyethylene resins that make it very strong yet flexible when used in the K-Line system. This tubing can withstand the effects of abrasive soils, kinking, freezing, the damage from UV light, and the various stresses exerted on the tubing while moving from set to set. K-Line tubing is available in 32mm, 40mm, 45mm, and 50mm sizes. The tubing has green stripes and tick marks along the length of the tubing that help in identifying the size of the tubing at a glance and to assist in the installation process.