Top bulb (box class). My lights were real good test Friday but after the long week of getting ready I was dragging on Saturday. I never got home Friday night and to bed till 1am and I drove up to the track 3 hours early to lay out and mount 4 pieces of diamond plates under my tires in my new trailer. Been kinda busting butt getting my new trailer ready for the race season. Like a ding-bat I adjusted my delay box to compensate for being tired and that bit me in the butt. LOL