16'' wheels on a '79

I recently found it mentioned somewhere, about 16" wheels for a 79 XS400...Didn't realize any were made this size for that bike. Just wondering, are they mag-style (I hope), or spokes?
Could see this smaller diameter wheel giving better acceleration and lowering the bike a bit as well.
Did they only come on certain bikes, or from any particular country or region?

The 80-82 used spoke and mag type 16" wheels. If your bike is a 79 with a drum rear wheel you would need the brake stay, chain guard and swing arm as the chain guards mount different. They handle a bit different and would rise the rpm's a bit. I run a 17 tooth front sprocket with mine. The rear sprocket is also shaped different as the wheel/tire is wider so it is an offset one.