Several Standard Colors Available for Standard and 45 Degree PostsFor Use With All Standard RailingsFor 2-3/8" (60.3 mm) Square Aluminum PostsCRL Standard Square Base Plates screws into Vertical Post raceways. They are countersunk to accept four Cat. No. BPS112 Base Plate Screws, then attached to the substrate with our Concrete Anchors or Lag Bolts. Use Stainless Steel Washers and Color Match Bolt Cover Buttons to add a finished look. The Offset Base Plate design allows vertical posts to attach to one side of the Base Plate.