ESI Bolt Base Plate Features: Mates to 12" H x 12" W Professional Box Truss W/Bolt Connection. Also Drilled to Fit F34 Trussing (Conical Connectors NOT Included.) Industry Standard Bolt Pattern 6 3/4" x 6 3/4" with 5/8" Holes. Four Convenient Hand Holes for Lifting. Slotted and Drilled for Easy Mounting. Load Tested & Inspected During Manufacturing and Quality Control. Includes one set of Four 5/8" - 11 x 2.5" (NC) attachment bolts, nuts, flat & lock washers. Compatible with most other 12" Professional Box Truss Manufacturers. Aluminum 1/2" Plate welded to 1" x 1.5" Solid Aluminum Extrusions for ultimate strength. Welded to TUV standards, 6082-T6 Alloy by GSI SLV-certified welders. Finish: Natural aluminum.