Birkenstock Gizeh Birkibuc Thong 100% Birkibuc Rubber sole Heel measures approximately 1/2" Platform measures approximately 40910 inches Original suede-lined cork/latex footbed Shock-absorbing sole Made of acrylic and polyamide felt fibers, Birkibuc offers a textured finish that looks and feels like nubuck Please see Sizing Chart for US size conversions As per Birkenstock, the Narrow & medium widths are usually differentiated by the sole imprints found on the the physical item & on the boxlabels, rather by M & N. Filled in footprint represents the narrow width and the not filled out outline represents standard/medium width. M refers to Men.