This is a Large Volume Fuel Filter that Can Be Used On R/C 1/10, 1/8 Glow Powered Models and in Airplanes. INCLUDES: One Filter Holder (Plastic) One 3X8mm Phillip Head Screw with a .5mm Coarse threads One 3mm Nut One Metal Filter Screens 10.5mm across .006" thick (One is already installed) One Black Rubber O-Ring to Seal the End To The Main Body Part Outer Diameter: .518"(12.5mm), Inner Diameter: .379"(9mm) Thickness .069"(1mm) One Filter: Overall length from tip to tip is 2-1/16" (52.5mm) Overall Diameter: 17/32"(13.5mm)