This plate is used diamond orientation for mounting to either vertical or horizontal masts. This plate is set up to use both 2.0"HD and 3.0" U-Bolts. The horizontal uses the 3.0" U-bolts. The vertical side has has holes to accommodate 2.0" HD and 3.0" U-bolt sizes. This plate is used on Log periodics like our 7&10-30LP8.