Some Motorcycles need an adaptor for your LED Bulb because the bulb seems to 'flicker' or interferes with Radio reception. That's because the electrical system of the motorcycle is 'looking' for a 55-65 Watt bulb.
The most common of these are the H4.
The H4 is for connecting the three-blade bulb to a three-blade headlamp bulb plug on the motorcycle. it looks like this:
Only $8.99 each!