The Dessa boot appears to run slightly smaller than some of my other Wittner heels. I purchased a 41 and it’s a good fit if just a little tight at the ankle. Heel height on the 41 is 13cm
Hope that helps
I reckon they have a new buying team as the range of heels is improving. Got my eyes on a couple of pairs of ankle boots plus maybe the red patent version of the Blossum pumps I purchased & posted recently.