Dune London Women's Sibyl Black Block Heel Over The Knee Suede Boot 8M / EU 39

on the box is written size 8 M / 39
the boots are written size 9M / 39
I made a screenshot from the manufacturer's website with a sizing grid. If there are additional questions about the measurement, please ask.

The Dune London™ Sibyl boots feature a form-fitting silhouette.
Textile and leather upper.
Pull-on style with self-ties.
Almond toe.
Man-made lining.
Lightly-padded footbed.
Covered block heel.
Man-made outsole.