Premira Electronic Ballasts construction is the leading ballast in the industry. The small lightweight design is up to 44% lighter than average magnetic ballasts. Our electronic ballasts have a low THD, less than 10% Total Harmonic Distortion. Maintenance Engineering Ltd. uses lab tested 50-year components that maximize lamp life, by staying in spec. Maintenance Engineerings premium quality ballasts are designed for a long life. These ballasts use rivet style soldering, which is vibration resistant, and ensures excellent electrical connections. Premium quality ballasts also use metal heat sinks which transfer heat away from the critical electronic components. Maintenance Engineering pots its ballasts with a silica based fill compound which resists leaking and aids in heat dissipation. Now that is a premium quality ballast.