Rainbird FPT X Compression Adapter Easy Fit Fitting, 1/2" Easy Fit Compression Fitting System - 1/2 in. Female Pipe Thread Adapter - Great for maintenance and retrofitting existing systems Faster and easier to install-requires up to 50% less force to install tubing, making your installation project faster and easier Works with virtually any manufacturer's 1/2 in. tubing, where the outside diameter ranges from .630" to .669" (16mm to 17mm) The eight components of the Easy Fit System (3 Fittings and 5 Adapters) can be built into over 160 different configurations Not compatible with Rain Bird XBS or XT700 tubing - Easy Fit Adapters are not barbed fittings; they are to be used only with Easy Fit Compression Fittings