handle bar riser sizes

Hello,

i'm looking to buy a set of handlebar pull back risers for my dragstar 650. I'm a bit (to say the least..) confused about size...

I find a lot of riser sets on internet dealers, but like 90 % is for harley.....

also don't want to order in the states, i'm not so patient to wait for 8 weeks or so.

Basically, the diameter of the risers i have now is 32 mm (so 1 1/4 inch i guess).

Is that some kind of standard in motorcycles, or are sizes between brands different?

Also, when they speak of 4 inch risers, is that 4 inch from the point of the upper plate, or from bottom of the riser (as they are still more than 1 inch inside the upper ball plate..

So as you see, confusion is complete. All help very welcome

thanks

Peter