The Builder’s Best V330 PRO Semi-Rigid Flexible Aluminum Duct with one crimped end and one plain end is a non-insulated Class 0 metal duct designed for safe, efficient, and reliable venting in general air supply, return, and exhaust applications. Built for performance and durability, it offers a strong and flexible solution for dryers, exhaust fans, and HVAC systems. Constructed from 100 percent aluminum alloy, the V330 PRO is corrugated and spiral-formed with continuous lockseams to ensure strength and maintain shape during installation. This model features a thicker wall than the Builder’s Best V320 duct, providing greater rigidity, dent resistance, and long-term durability in demanding environments. The crimped end allows simple joining to compatible fittings or additional duct sections, while the plain end provides a smooth, secure connection on the opposite side. Each duct measures 8 feet in length and ships compressed to 24 inches for compact packaging and easier handling. The V330 PRO is rated for positive and negative pressures up to 6 inches water gauge and supports maximum air velocities of 5,000 feet per minute. It operates across a wide temperature range from -100°F to +430°F, offering dependable performance in both cold and high-heat conditions. Meeting Class 0 requirements, the non-combustible aluminum construction achieves a flame speed of 0 and smoke developed value of 0, ensuring compliance with safety standards for metal ducts. Proudly made in the USA, the Builder’s Best V330 PRO Semi-Rigid Flexible Aluminum Duct provides a durable and code-compliant option for residential, commercial, and industrial ventilation systems.