Indoor grounding bar parts: copper bar,C bracket, pipe,spring washer,nut, expansion bolt, flat washer, threaded rod, insulator Part Name Spec1. copper bar 18x18x1722. C bracket3. Pipe4. Spring washer M85. Nut M86. Expansion bolt M8 x 907. Flat washer M88 Threaded rod M8 x 609. Insulator10. Screw M8 x 12 Grounding Bar