Universal i-LED Ultra 7440/7443 CK Switchback Pair (LED974CK)Description When it comes to high performance LED Bulbs; the numbers game is simply an excuse for a lack of engineering, and GTR Lighting isn't here to play that game. The i LED bulbs from GTR Lighting are here to win, and when you see them next to the aging competition, you won't worry much about the numbers. Ultra Optics: The optical system on the i LED bulbs is highly effective at maximizing output. It projects a considerable amount output forward