Working with 4-inch square tubing on a project? These end caps/plugs give your work a clean, finished look while keeping dirt and moisture out. Brand new, unused, in original packaging. The MPN is TP4.0, brand is IN HOUSE. They're not modified, not a custom bundle, and they're domestic products. Super simple but super useful! Perfect for furniture builders, railing installers, fabrication shops, or DIYers working with square steel tubing. Slip these caps onto the ends of your 4\ square tubes to prevent sharp edges, improve appearance, and protect the tube interior. They also add a bit of structural rigidity to the ends. Installation couldn't be easier - just tap them into place with a rubber mallet. Use them on outdoor furniture to keep water out of the tubes (prevents rust from inside!), on handrails for safety, on equipment frames, or any project using 4\ square stock. They give a professional, finished appearance to otherwise rough tube ends. No UPC, but that doesn't matter for something this straightforward. Buy several - you'll always find uses for them! Whether you're building a workbench, gate, shelving, or custom furniture, these end caps are the finishing touch that makes your project look store-bought instead of homemade.