Birkenstock Unisex Zermatt Slipper Size:40 If you plan to wear

If you plan to wear thick wool socks or want a slower break-in with thicker insoles

The slip-on has no laces to adjust — if you have a high arch

hidden elastic strap under the tongue for snug fit

women's 9 = unisex 7

Birkenstock Unisex Zermatt Slipper Size:40 If you plan to wearThe Birkenstock Zermatt is the brand's flagship slipper a closed toe house shoe built on the same iconic cork and latex anatomical footbed that defines Birkenstock's sandals. Wool felt upper with a soft warm lining keeps feet comfortable indoors year round and on short outdoor trips. Made in Portugal. The footbed molds to your foot over the first 12 weeks of wear, the same way the brand's sandals do. Fit notes: Birkenstock uses European sizing. EU 36