These shock mounts are CNC machined in-house from aircraft quality 4130 chromoly. They are 1.50" OD and have a 1/2" ID for a grade 8 or higher bolt to use. You can use these for an engine cage up front, a bedcage in the rear or a removable component. Combine the single taper versions with the dual taper version for a coilover and bypass shock side by side configuration. Sold in pairs.