Right here.

http://www.buyplaneparts.com/content.asp?id=178

Try http://www.floatsalaska.com/default.aspx

I bought one and like it.  I am waiting for a second, broader beam unit.

I just installed the Knots 2U HID's in my C172D. I'm very pleased with the results and how nice the installation went. I purchased them from Texas AeroPlastics ($550.00 each)who is the distributor for the manufacturer, Knots 2U.

The whole system is guaranteed for life as long as you are the owner of you aircraft. That's cool, since the parts are expensive.

True to their word, they only draw 3.1 amps each and are so bright, they can be blinding if you look at them even from a 20 degree angle from center. I can now leave them on, day and night, without the replacing the old GE 4509 bulbs every time I turn around. Highly recommended!

BTW, each ballast is very thin and they mount on each wing rib to the left and right of each lamp.

I installed one sport light for landing and one flood for taxi. You can use whatever combination you like.

Rich

I'd love to have one in my Skyhawk, but $500.00 for a light bulb? Yikes, that'd pay for the annual.