BMW and touratech has a resistor in the LED so you would be able to install no issues, if you use others without a resister and replace all four you need a soild state flasher, SAR (sick ass racing )has them pretty cheap. If you only replace 2 of your turn signals with LED you have no problem with the OEM flasher
Our famous last words "It doesn't look too bad".
08 KTM 450 EXCR
2010 BMW F800GS