Amazon.com: Blue Boar Recessed Light Carbide Grit Hole Saw 4-3/8” Dia for 4 inch Lights: Fast Cutting in Drywall, Lath & Plaster, Hardi Board - Ships Within 1 Biz Day from NV :
Install Recessed Lighting Over Computer - The San Fernando Valley Sun
How to Convert a Ceiling Light to a Recessed Light
Amazon.com: HLOFIZI 4-1/8 Inch Carbide Hole Saw for 4" Recessed Lights, Cutting Plaster Drywall Ceiling Sheetrock, 2X Faster : Tools & Home Improvement