These socks are really nice.  I got them to wear with my prima loft slippers on my super ice cold floors and they do the trick.  When I take them off my feet are toasty warm to the touch.  I wear a woman's 9 and the 8.5-9.5 is a perfect fit.  I have another pair of fleece socks from another manufacturer that do not have a defined heel and they tend to move around just a bit.  These Acorn socks have a defined heel and they stay in place and fit better.  The material is the right amount of thickness and very soft.  While I wished there was a better selection in my size I am not complaining....and they arrived in my mailbox two days earlier than the first date of the estimated shipping window!  I love my socks.