Mountain bike 26" wheel nut

[rliu]

Hello I'm looking to replace this nut (http://www.flickr.com/photos/rliu/5762546078/) does anyone know what size/description it is and where is a good stockist?

 

[lpretro1]

Hard to see exactly from iccy but It looks like a standard 15mm track nut - your LBS should have one.