These are extremely lightweight and almost like socks with a bit of padding on the bottom.  I bought them to wear around the house as I work from home and like to pace around while I'm on conference calls.

The reviews on get a size larger is absolutely true.  I'm a size 13 and the 12-13 are more like 11-12.  my toes were already beginning to feel cramped 30 seconds after having them on.  Then my feet started sweating.  So they were tight and not breathable at all.  Went to return them the same day I received them in the mail and had to pay $7 return shipping!!  I could have just gone to a local store.  If you like your feet to sweat this are otherwise pretty comfortable as long as you get a size larger than you are... I didn't have that option being 13 already.