Looking for high quaility push in fittings that will seal tight? duotight are the push in fitting with superior sealing capacity due to the double o-ring sealing design.Why do we use Double O-rings? The secret to our superior sealing performance is not just the fact that we use high quality EPDM o-rings but also use two of them. The double o-ring means we literally have twice the sealing surface surface when compared with other push in fittings. This makes our fittings even more reliable and reduces the chance of a leak significantly.The double o-ring system also means that we can bend the hose with much tighter radius without causing leaking issues. This typically can be an issue with other fittings. This combination of factors makes duotight fittings the most reliable push fit fittings on the market.Compatible with our KL06224 – EVABarrier 4mm ID x 8mm OD line KL06231- EVABarrier 5mm ID x 8mm OD line KL42741 – Red EVABarrier 5mm ID x 8mm OD line KL42765 – Black Lightshield EVABarrier 4mm ID x 8mm OD line Not compatible with 6mm ID x 10mm OD lineNo clamps necessary! We do recommend cutting your hosing straight, not on an angle, to ensure the line has a complete seal. To remove the fitting simply push in the collet and the hose can be removed. These push in fittings are suitable to be used up to 100 psi.This Tee Piece is suitable for our EVABarrier Beer & Gas hosing in 4mm ID & 5mm ID lines or most lines with 8mm outer diameter.It will not fit the 9.5mm OD EVABarrier line (with 6.3mm ID) but we do sell these larger 9.5mm duotight fittings separately.These push-in fittings have been engineered for maximized performance in both gas and liquid applications. Compared to other push-in fittings on the market, duotight takes the double safety approach to all of the connections with two EPDM o-rings per hose port. No other push-ins on the market have EPDM o-rings, let alone two! per push-in connection.What is EPDM? EPDM = Ethylene Propylene Rubber which has excellent chemical resistance including being compatible with ozone, oils, wide variety of alkaline and acid compounds, water, alcohol, ketone, and beverages.EPDM is also resistant to aging, and weather and will not perish easily like other rubber compounds. When compared with silicon and vinyl EPDM has better gas transmission rates, better wear resistance, is BPA-free and is the number one choice for many long-lasting food-grade applications.