OZ-Gedney Reducing Washer, Steel, Finish: Pre-Galvanized Zinc, 1-3/4 IN Outside Diameter, 0.88 IN Inside Diameter, 1 X 1/2 IN Conduit, Third Party Certification: UL File Number E11857, CSA 057250, Applicable Third Party Standards: UL 514B, CSA C22.2 No.18, NEMA : FB-1, For Used To Reduce The Size Of A Knockout Or Slip Hole