LED Fluorescent Lamp Highly energy-efficient, bright and white. Exclusively for rapid start fixtures. You can switch to LED simply by replacing the lamp in the existing fixture. However, this is only for rapid start fixtures. For fixtures with two lamps, both must be replaced. Cannot be used with fluorescent tubes. Please do not bid if you are unsure. We are not responsible. Thank you for viewing. Only two were used a little, the other four are unused.