If you wear socks with your slippers I would probably go with 2 sizes up, but I wouldnt suggest socks with these, for one, they are way too tight to wear with socks and two they make my feet sweat. However for sound quality to price performance, its 5/5. Its still as good as new, no issues and Im very satisfied with what I got for the price. What is Amazon asking me to rate the thickness of items today. This extension cord affords ONE socket and does the job at a reasonable price. 2: Having had a set of 5. Zu eng im Spann Theyre extremely warm which I normally shy away from because I tend to run a little warm myself, but these are actually a comfy warm. My computer detects a mic, but after much trial and error, it appears to be dead. Fat tires.