3-1/8", Recessed Light Hole Saw, Includes Grit Edge Hole Saw & Pilot Bit, For Cutting Through Drywall, Plaster, Acoustical Tile, Ceiling Tile & Stucco With Wire Mesh Backing To Install Recessed Lights, For Installing 3" Recessed Lights, Fully Sealed Clamshell, Compatible With Arbor TV #138-923 & TV #139-793.