Orbit Industries„¢ Fixed Position Box Mounting Brackets (FMB Series) support 4½, 4-11/16½ 5½ Sq. Boxes between wood or metal studs. The FMB-16 mounts 3 boxes in a 16½ stud bay; the FMB-24 mounts 4 boxes in a 24½ stud bay. Save costs by standardizing on 4½ Mud Rings for all box sizes. 4½ mud rings can also be mounted on their own for low voltage applications. The FMB Series speeds up installation as boxes are evenly spaced apart to eliminate any measuring and improves the quality of final installation with consistent box placement. Features (Updated 2/2024): - Compatible with 4", 4-11/16" and 5" square boxes- Mount 3 boxes and/or rings with FMB-16 and up to 4 boxes/rings with FMB-24- Unique key-hole pattern allows box to be turned 90° and holds any size box in place when ring is removed- Use 4½ rings on any size box (horizontally and vertically)- 4½ rings can be mounted on their own for low voltage applications using 8/32 screws- Low profile design limits drywall bulging- Bendable latch tabs securely hold 4" or 4-11/16" sq. box in place without need to tighten box screws. Skip hassle of tightening box screws until the final ring installation, making installation process more efficient and convenient.For a Flat versions, please see FB-3 and FB-4. Specifications: Material Sheet Steel Color Galvanized Certifications: UL File Number: E310661 Literature Cat. No. UPC Description Std.Pkg. FMB-16 8-35243-00681-2 Fixed Position Box Mounting Bracket for 3-Boxes on 16" studs 25 FMB-24 8-35243-00682-9 Fixed Position Box Mounting Bracket for 4-Boxes on 24" studs 25