I had these put on my 1991 K100RS before our trip to Bloomsburg. I had these put on both for the added lights for daytime and since the eyes aren't quite what they used to be, for extra light when traveling after dark.
We took a trip two weeks ago to Phoenix and left after I got off work at 8pm and rode to Laughlin, NV. Really the first time I was able to see how well they worked at night, really impressive !!
I bought them from the "Twisted Throttle" web site. The kit had everything except the proper mounting brackets, so had to add them to my order, needed the M6 bolt size bracket to fit my bike.
Total cost $347.00

Close up

I had the BMW shop install them ( I have the mechanical aptitude of a trout ). They worked fine, but the shop wired them to my bright light switch, so I couldn't use them at night. I had a friend change the wiring hookup to my parking light, so now they are always on when ever I start the bike - I like this setup much better.
Here is some night time shots of how good they work - really light up the road for better night driving.
Donna was my test subject, she is wearing the BMW jacket that has very good reflective material sewn into the jacket, and was about 70 feet from the bike.
Regular low beam
High beam

Denali lights on with the low beam

Quite a difference - we couldn't get any night shots while riding, my camera kept adding the flash.
Mounted on the lower front forks


The on/ off switch is not of the highest quality, I just leave them on all the time - has a yellow light when the lights are on, had the switch put through the little vents beneath the right handle bar

Here is how they look coming directly at Donna taking the pics, no flash added



One of the best additions I have added. I also looked at the same product made by Clearwater - but they were about $100 more.
Plus, they look really good on the BMW, almost factory looking.