Modular square steel guard rails without toeboards steel guard rail systems provide an economic way to protect people and machinery. The modular design allows for maximum versatility. steel guard rails are great for loading docks, floor openings, walkways and mezzanines. Guardrails are made with heavy duty 13-gauge 1-5/8″ square tubular steel with high visibility yellow powder coat finish. Each section includes 2 rails and 2 upright posts. Measures 42″h overall with 21″h mid-rail.