Fitting SizeAcceptable Inside Tubing DiameterMaximum Operating Pressure1/2".590" to .630"40 PSI3/4".790" to .845"40 PSI Barb Tubing End Caps are double barbed fittings that provide high retention in low pressure poly tubing making very reliable connections. These can be confidently installed without clamps when matched with quality low pressure poly tubing with corresponding inside dimensions. Operating pressures should not exceed 50 psi.Features:Double barb for increased retentionSharp-edged barbs create leak-proof sealIncreased strength and superior qualityHeat, chemical and wear resistantUV stabilized materials for long lifeAvailable Sizes: 1/2" (16mm) and 3/4" (21mm)Applications: Low pressure micro irrigation systems.