Those are car headlights, right? They're made to be used in pairs if they are, and one alone on a bike may not have the best pattern. Specific motorcycle headlights are usually marked as such and have a different pattern (fluting in the lens) than a car headlight. I got a nice original H4 from am 850 triple off eBay for my '83. I knew it would swap and fit because the chrome ring is the same part #. I got the complete headlight, bucket and all, for around $25. I thought that was a good deal and I was more than willing to pay that for an original Koito light. Heck, aftermarket ones cost about the same.