Trek Mountain Bike Kickstand

I have a TREK 810 MTB Singletrack?
no support and where the bike would normally attach a crutch is there, but is a little different then the other bikes I've had. usually a bicycle has a square piece of metal at the bottom of the chassis at the front of the rear wheel with a hole in the superior. but this bike has a round piece of metal with a hole in the side. The important point to make is what kind of crutch should I buy?
We shop for the right.

