Quality barbed fittings provide high retention in low-pressure poly tubing for long-term reliability of connections. The acetal fittings can be confidently installed without clamps when matched with our quality low-pressure poly tubing with corresponding dimensions. See note below on gray PVC fittings.Features:Sharp-edged barbs create leak-proof sealIncreased strength and superior qualityHeat, chemical and wear-resistantUV stabilized materials for long lifeSpecial Note: 1/4" barbed fittings have the unique ability to be "snapped" into larger tubing after punching a hole into the side of the larger tubing with any of our 1/4" punch tools. This creates a water-tight seal and allows you to "tee-off" of larger diameter tubing using only 1/4" fittings and a hole punch. Use this Barb Tubing Tee insert fitting to connect three sections of tubing together. Fitting SizeAcceptable Inside Tubing DiameterFitting UseMax Operating Pressure1/8".125"To connect sections of 1/8" tubing or to connect 1/8" tubing to mainline tubingUp to 30 PSI1/4".170"To connect sections of 1/4" tubing or to connect 1/4" tubing to mainline tubingUp to 30 PSI1/2".570" to .620"To connect sections of 1/2" poly tubing togetherUp to 30 PSI3/4".805" to .820"To connect sections of 3/4" poly tubing togetherUp to 40 PSI1"1.06"To connect sections of 1" poly tubing togetherup to 40 PSI