Dual-intensity, LED bulbs are replacements for standard bulbs. Three brightnesses to choose from. Switchbacks are normally white and blink amber.
18-chip: 165 Lumen
45-chip: 220 Lumen
28-chip: 550 Lumen
60-chip: 150 Lumen
Bulbs are sold individually. You will need load resistors to eliminate bulb-out errors.