The Isotoner Ballerina Slipper is beyond a doubt, the best slipper I have ever worn. I like the satin slipper the best and just bought a pair in ruby red, love the color.  They fit my feet like a dream, stay on my foot and are like a second skin.  I wear a size 10W shoe and I buy the XL slipper and it fits perfectly.  No complaints at all.  I hope they always have this slipper available.