Thank you to the customer that left a review regarding sizing!  I wear a solid size 10 in all shoes.  I have never ordered an X-large 11 - 12.  However, I took a chance after reading the review that these Dearfoams slippers run small.  I can't speak for other Dearfoams, but the X-large 11-12 in this style fits perfectly and I would not want them any smaller.  I gave the product itself 5 stars as they are so comfy!