You are looking at a 2.50" 90 degree rubber coupler for use in supercharger and turbo applications where a quality coupler is needed. These are made of the same material Procharger uses in their rubber couplers. Please view the pictures provided as it will come exactly as shown. 2.50" Inside Diameter. Measurements are shown in the pictures. The price is for one coupler. I have a few available. Thanks for looking! **I also have 2.50" 45 degree couplers available in another listing.**