I would recommend going up one size as it is a 1/2 size smaller in fit. pair of Skechers in the wedge style I thought I knew what size to get. A good quality hex tool was included which is all that is needed to install. In comparison I purchased some Chaco ZX1s and found the Tevas to be much more comfortable as the webbing on the Chacos chafes even though Ive worn them in and had them over a year. If youre 25cm you should get the 8. Super easy to install as well! HUZZAH-Its pretty. I wish I could say it was a super easy setup but there were some slight issues with pairing the device to work with Alexa and also to get Spotify registered. So it does it?s job in keeping shoes in an organized fashion. This story really lifted my spirits.