Ferplast Ergotrekking Harness, black

Had to send it back. My little dog weighs 9.5 kg and has a chest size of 54, but can't fit into size S. It's so small that I didn't even try it on. I'm considering ordering a bigger one, but I'm worried that M might still be too small.

According to the centimetres listed on Zooplus, I ordered the harness in size S. It should have fit. However, the harness is too small and unfortunately has to be returned.