Thick cold-rolled steel plate, Baking paint surface Inlet plus water-proof rubber plug Plenty of internal space 2. The box body is made of 1.0mm thick cold-rolled steel plate,which is resistant to pressure, impact, and not easily deformed 3. Wear resistant, Waterproof, Rust proof, Environmental protection,Beautiful and generous, Long service life 4. It can avoid the fiber optic cable entering line from scratching the fiber optic cable,and is dustproof and waterproof 5. Simple structure, clear internal structure, clear at a glance, convenient installation, greatly reducing cost