One-piece mirror polished 304 stainless steel, 3D cross four-way through structure, four ports with unified caliber fit standard round handrail tubes, pre-drilled set screw holes on tube wall. Used for three-dimensional intersection splicing of multi-layer handrails on stairs and balcony railings, realizing simultaneous connection of four-way tubes up, down, left and right. Integrated molding delivers strong pressure resistance, two installation options of welding or screw fixing, waterproof and rust-proof for all kinds of indoor and outdoor guardrail projects.