Get this 8 - pack of 45 - Degree Angle Support Brackets for your wooden projects! These brackets are made of high - quality thickened Q235 steel with 304 stainless - steel screw fittings and a professional black outdoor high - temperature powder coating, ensuring they're waterproof, rustproof, and corrosion - resistant. They fit standard 4x4 (actual 3.6"x3.6") wood joists, but remember to cut and sand the wood joists at 45° at both ends. Installation is a breeze: just sand and trim the wood, snap the crossbeam into the brackets, and fix the screws. The drain hole design prevents water ponding. They're suitable for a wide range of projects like slides, gazebos, and tree houses, providing reliable support and enhancing the stability of your wooden structures.