A typical price for Electrical Box Mounting Brackets is $6 but can range from approximately $1. Rest assured that even if water enters the security junction box, it will not affect the normal functioning of your camera. The junction box is specifically designed to neatly conceal the excess wires. Durable: The bracket is made of stainless steel, reinforced and thickened, anti-corrosion and rust-proof, strong and durable. Adjustable: The diameter is 300mm, which can be used to install various poles within this diameter range. ✓ Top-Brands ✓ Low Prices ✓ Latest Trends.