ITEM: #3017 2 Gang 1/2" Mud Ring Size: 1/2" Drywall Flange Depth Fits Metal 4"x4" Square Metal Box UL Standard Certifications Intertek Warnock/Hersey 2-Hour Fire Wall Rated ASTM E-119-03 & ASTM E-814 (UL 1479) UL 514C 3rd Ed. - CAN/CSA 22.2 NO. 18-98 Product Features Converts Metal 4 square box to support Cheetah Devices Slots for screws on diagonal corners High Strength Polycarbonate Composite Patent Pending Speed Anchor System