The LB Fans 6 Amp Single Phase 5 Step Auto Transformer (model SPM5060) is a reliable speed controller designed for use in commercial ventilation systems. Offering five step speed adjustments, it allows precise control over fan performance while ensuring minimal motor noise and eliminating magnetic hum. The unit includes a convenient ON/OFF switch for straightforward operation. Built for durability and consistent performance, this controller is part of the LB Fans Controllers & Sensors range, making it a suitable choice for a wide variety of ventilation applications.