Self-piercing drippers from Netafim USA are for use with blank polyethylene tubing, Techline® CV, Techline®,other Pressure Compensating and Non-Pressure Compensating dripperlines. The drippers install on-surface or subsurface and work well among wide-spaced plantings, trees and vines, hanging baskets, flower boxes, planters or pots. THey feature an anti-siphon operation which prevents contaminants from being drawn into the dripper and are easy to install, no tools required.