These are made to fit to mount the mechanism to the mech board using the inside mech cup washers and rubber mounts. BUT they were made with the wrong thread.  They are beautifully chromed with correct domed head and slot but has the thread of 5/16-18 and the mechanism requires a thread of 5/16-24.  You can use them but you will need to re-tap your frame, or could be used in other areas.  Length of these are 2.5 inches long (ridge of head to end of bolt).  We will not accept returns or exchanges on these for any reason. Being sold as-is.