I have a pair of 15" Old Stamp Istanbul K hats. I use them with a Yamaha HS 740 stand. The clutch does fit the hole of the hat, but it is threaded all the way through so be watchful for potential key-holing. The cymbal seat centre-piece is slightly too wide though to fit the hole. What I did was sand and file the plastic centre-piece down, decreasing its diameter, so that it now fits the hole. It doesn't take much work to do this and the result is great.
Here is a pic of these Yammy stands:
[img]http://images.static.steveweissmusic.com/products/images/uploads/1126063_12604_popup.jpg[/img]
/Magnus