4 foot LED Light for replacement of fluorescent tubes. Requires minor rewiring to bypass ballast. THIS LIGHT TURNS ON WHEN YOU FLIP THE SWITCH. A simple, bright and more efficient replacement for existing fluorescent light bulbs. Try Just One Pair and You Will Never Go Back to your annoying fluorescent. NOTES: 1. All bulbs in the fixture must be changed to Nature's Electric LED bulbs. You cannot mix fluorescent and LED bulb in a fixture. 2.1 Pack contains 1 tube - buy 2 ea 1 Packs or 4 Pack for 2 bulb fixtures