iMBAPrice BE1R-2 (2-Pack) 1-Gang 4.35-Inch x 1.5-Inch Plastic Electrical Ceiling Box Extender for 3.5" and 4" Round or Octagonal Boxes - Amazon.com
4-11/16 in. Square Extension Ring, Drawn, 1-1/2 in. Deep with Eight 1/2 and Four 3/4 in. KO's: Electrical Boxes: Amazon.com: Tools & Home Improvement
Hubbell Raco 665 Single Gang Extension Ring - Amazon.com
Sigma Engineered Solutions, Gray Sigma Electric 14223 1-Gang Extension Ring, 1 Count (Pack of 1) - Electrical Boxes - Amazon.com
Hubbell Raco 4 in. Octagon Extension Ring, Drawn, 1-1/2 in. Deep, Two 1/2 & Two 3/4 in. KO's (130): Ceiling Fan Remote Controls: Amazon.com: Tools & Home Improvement
Amazon.com : Evertech 4pcs 5mm Camera C-Mount Lens Adapter Ring Extension Tube C to CS Mount Lens Black Aliminum Adapter for Most Types of CCTV Security Cameras : Electronics
BELL 5407-0 2-Gang Weatherproof Extension Ring, 1-1/32 in. Deep, Gray - Electrical Boxes - Amazon.com
Hubbell Raco 665 Single Gang Extension Ring - Amazon.com
Steel City 53151 1/2 3/4 Pre-Galvanized Steel Square Box Extension Ring with 1/2-Inch and 3/4-Inch Knockouts - Ring Terminals - Amazon.com
Raco Incorporated 243139 Deep Steel Octagon Extension Ring, 4 by 1-1/2-Inch - Electrical Boxes - Amazon.com
2 Pcs, 4 in. Round Pan Box Extension Ring, 1/2 in. Deep, Zinc Plated Steel Used to Mount Ceiling & Wall Lighting Fixtures to Provide Additional Wire Capacity - Amazon.com
Amazon.com: Steel City 55151-1/2-25 4-Inch Diameter 1-1/2-Inch Deep 15.8-Cubic Inch Pre- Galvanized Steel Octagon Box Extension Ring : Industrial & Scientific
Steel City 59361-1/2 Handy/Utility Outlet Box Extension Ring, Drawn Construction, 4-Inch Length by 2-1/8-Inch Width by 1-7/8-Inch Depth, Galvanized - Outlet Plates - Amazon.com
RACO 187 Drawn Extension Ring, 22.5 Cu-in, 4 in L X W X 1-1/2 in D, Product Specific - Amazon.com
1/2" Octagon Box Ring Extension - Amazon.com
Amazon.com: Steel City 55151-1/2-3/4 4-Inch Diameter 1-1/2-Inch Deep 15.8-Cubic Inch Pre-Galvanized Steel Octagon Box Extension Ring : Industrial & Scientific