iPower 600 Watt Digital Dimmable Electronic Ballast for HPS MH Grow Light Support Dual Voltage Input 120V/240V; Dimmable Options: 50%, 75%, 100%; (8 Feet heavy-duty power cord included) High frequency output results in less power loss, 30% more lumens than magnetic ballasts for improved yields Automatically converts between HPS and MH light bulbs by micro-chip programming; Fast lamp ignition by lighting up the bulbs within 1-2 mins max; Stable voltage output ensures flicker free light Ultra-Safety: Protection against Short Circuit, Power Surge, Ignition Failure, Overheat, End-of Bulb-Life; Built-in cooling fan and graduating fin designed to minimize ballast temperature Quality Assurance: CE certified and UL listed; Warranty: 2 years