Birkenstock - Sierra Rugged. Color Black Oiled Leather 1. Low Stock. On sale for $101.50. MSRP $145.00.. 3.8 out of 5 stars1 left in stockBrand NameBirkenstockProduct NameSierra RuggedColorBlack Oiled Leather 1Price$101.50MSRP: $145.00Rating4Rated 4 stars out of 5(51)