Designed, manufactured and assembled in the UK by John Guest Speedfit. Connectors use a grip then seal collet arrangement. The female coupler is ideal for the connection of taps, and Toilets. Simply push the fitting fully onto the pipe and turn onto the thread. Should the need arise to demount the connection unlock the nut push the collet towards the body of the fitting and pull the pipe to release. Acetal has greater strength and heat resistance compared to polypropylene. The fittings are manufactured in acetal copolymer with food grade nitrile O-ring, making them especially suitable for applications involving foodstuff and potable liquids. They are also suitable for air and inert gases and can therefore be used on CO2 lines, pneumatic applications and vacuum. Material : Acetal National Pipe Thread (NPT) Size Measured Against a Ruler* Actual Diameter (Inches) National Pipe Thread (NPT) (Fractional) 0.405" 1/8" 0.540" 1/4" 0.675" 3/8" 0.840" 1/2"*NOTE: A very common misconception is that a 1/4" NPT measures as 1/4 inch on a ruler or tape measurer. However, that is not the case. NPT will measure larger in diameter. Above is a sizing reference to help clarify. Additional Details ------------------------------ Product description: Designed, manufactured and assembled in the UK by John Guest Speedfit. Connectors use a grip then seal collet arrangement. The female coupler is ideal for the connection of taps, and Toilets. Simply push the fitting fully onto the pipe and turn onto the thread. Should the need arise to demount the connection unlock the nut push the collet towards the body of the fitting and pull the pipe to release. Acetal has greater strength and heat resistance compared to polypropylene. The fittings are manufactured in acetal copolymer with food grade nitrile O-ring, making them especially suitable for applications involving foodstuff and potable liquids. They are also suitable for air and inert gases and can therefore be used on CO2 lines, pneumatic applications and vacuum. Material : Acetal National Pipe Thread (NPT) Size Measured Against a Ruler* Actual Diameter (Inches) National Pipe Thread (NPT) (Fractional) 0.405" 1/8" 0.540" 1/4" 0.675" 3/8" 0.840" 1/2"*NOTE: A very common misconception is that a 1/4" NPT measures as 1/4 inch on a ruler or tape measurer. However, that is not the case. NPT will measure larger in diameter. Above is a sizing reference to help clarify.