The Matthews Three-Way Box Corner is the quiet hero of custom box and frame builds. Designed for use with 1" and 1-1/4" square tubing, it's the essential hardware solution for constructing overhead soft boxes, rag frames, and window tenting rigs — including the industry-favorite “day-for-night” window tent to achieve dramatic moonlit realism. Side braced for strength and finished in non-reflective grip-world black, each corner includes set screws to secure tubes in place, while still giving you the flexibility to remove them and swap in T-handles (if you want that classic twist-grip feel). The slim side gusset doubles as a built-in tie-down point, making it ideal for securing fabrics, diffusion, blackout, or safety cables without added straps or tape. 1" and 1-1/4" sizes work standard for any overhead frame pieces or tubes from your local metal supplier. Whether you're rigging lights overhead, tenting in a window, or building a custom soft box on location, this is the original hardware that grips trust. Often imitated. Never replaced.