BIRKENSTOCK Shearling Boot Nut BROWN Leather Suede ZIP up US 6  EU 37 

These boots are an older model and I no longer remember the name of it.  They were bought for my daughter but she never got to wear them (it's never cold enough where we live).

They're a mix of suede and leather with fur top and lining.  I see no information on what the fur is, but I assume it is the Australian shearling used in the Arizona sandals as it feels the same.

The insole is cork and made in Germany.