threaded PDE Series Plastic Threaded Plugs for Flareless Tube and Nut Assemblies PDE Series are designed to fit tube and nut assemblies with common thread sizes interchangeably. Knurled to aid with finger tightening installation and removal. Material: Low-Density Polyethylene Color: Red PDF Series Threaded Plastic Plugs for Flat-Faced O-Ring Hydraulic Fittings PDF Series are designed for easy mechanical or hand installation of flat-faced O-ring hydraulic fittings. 6 or 8 Ribs Equally Spaced * Fits common thread sizes * Fits common nominal tube sizes * Knurled for ease of use Material: Low-Density Polyethylene Color: Red PDF 40 and 80 PDH Series PDF 60, 100, 120, 160 and 180 Threaded Plastic Plugs for Flat-Faced O-Ring Hydraulic Fittings PDH Series plugs are designed for flat-faced O-ring hydraulic fittings and can be installed and removed with an Allen Wrench. The plastic plugs have a universal design with standard thread pitches to sit flush against an O-ring. * Common thread sizes * Flangeless style plug Material: High-Density Polyethylene Color: Red 128 * For other material and color options, contact customer service.