These were purchased to replace some of the terribly unreliable ballasts in some lights purchased from Big Box Depot. I like the simple wiring in this ballast. The ballasts they replaced used 6 wires to two lamps. You use 3 wires to two lamps. I like the fact that the failure of one bulb does not cause the second bulb to not light. They're quiet enough that I can't hear them, which is good. The length of the wires is sufficient. I could give them 5 stars if the "instant start" claim was spot on. Yes, I'm picky, but the start is delayed by about 1/2 second. It's fine, but the other "instant start" lights in my house work right away, so every time I turn them on I have a passing concern that something is wrong.