Here's the chain of events: Old Fixture removed, New Fixture Base Plate too small to cover apperture in mirror for workbox, Find source for "goof ring" that fits, Ahhh, 1-800 Ceiling's site made ordering a breeze. 3-4 day fabrication was completed in only one day so my mirrored goof rings were in my hands 4 days after ordered and installed on Day 7 of the project. The electrician loved that the goof rings were plastic as it diminished the possibility of it cracking if screws were snugged too much. 1-800 Ceiling is a great resource!!