After seeing an RT coming down the highway with a modulator and noticing how he really stood out from the surrounding traffic, I ran down to Kisan Electronics and installed one in my 1100RS. What a difference! I immediately noticed that people were a lot more polite and waited for me to pass when they otherwise would have just pulled out. Best insurance policy ever.
They come with a light sensor that only allows the modulator to function during daylight hours and only then when it's on high beam. Low beam turns it off in daylight. The sensor turns it off at night.
Some motorist find them a little annoying. But frankly, I find getting run over to be a bit annoying.
It could extend your life expectancy.