These 2.5 mm Cressi high-stretch neoprene boots add a thin layer between your feet and fins. A Metallite interior helps with putting them on, while the slip-resistant sole offers protection during brief walks around the dive site.
They can be worn in a full-foot fin to reduce rubbing or inside a sturdier dive boot when using an open-heel fin. Check both foot and fin fit with the added thickness. The merchant lists EU sizes from 38/39 through 45/46.