Carlon Pvc 3 Round Old Work Ceiling Box 18.0 Cubic Inch Capacity 2-3/4 Deep Captive Nails 4 Integral Clamps Zip Mount Retainers High Temperature Resistance Blue Ul Listed Bulk Discovery Con, Nbr, Sup, Hwu Price is indicated for bulk discounted quantity of 8 unit(s) per case. Material : Polyvinyl Chloride Manufcture : Thomas & Betts Part Number : B618RR-UPC Ceiling Round Old Work Box, 18 CUIN Capacity, 4" Diameter x 2-3/4" Deep PVC, 3 Swing Out Retainer Arms, 4 Integral Clamps, For Light Fixture Only, Not For Use With Ceiling Fans.