Badger skins.

There is much obscurity as to the meaning of the word tachash, rendered "badger" in the Authorized Version,

Ex 25:5; 35:7

etc. The ancient versions seem nearly all agreed that it denotes not an animal but a color, either black or sky-blue. The badger is not found in the Bible lands. The Arab duchash or tufchash denotes a dolphin, including seals and cetaceans. The skins referred to are probably those of these marine animals, some of which are found in the Red Sea. The skin of the Halicore, one of these, from its hardness would be well suited for making soles for shoes.

Eze 16:10