This is the only pair of GEOX that I bought off Amazon is true to size. Other style usually run small but this one is true to size.I’m a 39-40 and I purchased 41, as a result I do have some room.It does feel warm and waterproof. Downside is the inner black fur lining are falling off during your first few uses, sticking to your socks, your carpet, just everything.... once the loose fur all fall off, things are back to normal.Easy to put on and off, a bit slippery on the bottom, so I’m still debating if I’d wear it during heavy snow. Another thing is the boot is not very tall, so if snow is deep, don’t wear them out.