50w Resistor set.
Use if no flash after replacing the OEM flashers with LED flashers. Install in-line, one on the right side flasher and one on the left side flasher.
This will increase the load on the flasher relay and it will work as normal.
Most of the time you do not need one for each light - one for each side is enough. Install onto metal for better heat disposal (they get HOT after long time use)