Sioux Chief 886 series PushTite closet flange shall be used where necessary in drainage systems. Flange shall include holes for securing to floor and optional notches or slots for attachment of closet bolts. Inner diameter of flange outlet shall be at least 3 in and have smooth inner walls with no obstructions or ledges. Engineered elastomer flange gasket shall provide 3 points of contact to ensure a positive seal inside 4 in nominal DWV pipe. Always fasten closet flanges to the floor.