Nano-Cloth has no abrasive quality on it's on, so when using these strops, you're only getting the abrasive effect of whichever compound you apply. These are best used with sub-micron abrasives but also work extremely well with any abrasive gel, spray or paste.

August 10, 2012 Update - 

These are a hot new item and temporarily on back order. Please expect 2-3 weeks turn around on the Nano-Cloth strops.