5 mm neoprene. The seams of the boots are waterproof due to GBS assembly (Glued and Blind-Stitched): the neoprene is glued first of all, then sewn for maximum strength (the sewing needle does not go completely through the neoprene in order to prevent water infiltration).
Fit of the fin, sole and reinforcements
Stop system on the heel keeps the fin strap in place so that you do not lose it when diving.
Neoprene boots with flexible ridged rubber sole for better grip (non-slip). The upper is reinforced to limit the discomfort of adjustable fins.
These scuba diving boots provide thermal protection that has been tested by the independent INPP institute (Marseille, France) in order to validate their compliance with the current standard (EN 14225-1:2017)