THIS IS AN ADD-ON PRODUCT TO THE PRICE OF THE REGULAR PRICE OF SOLE OR HEEL REPAIR. The price is for the pair and is available in black, brown, beige or white. This product is spliced in the heel area after the repair is complete. The material has a harder durometer than the traditional Birkenstock soling material. As a harder material it should wear longer than the traditional Birkenstock material, but it may also have a firmer/harder heel strike when going through the gait cycle. The material is the SVIG Trekking compound made in Italy. It comes with two different tread patterns. The default on the black, brown or beige are on the left of the photo. The default for white is in the middle. The other black, brown or gray are substitutes or available upon request. The Trekking compound is a compact rubber compound that according to SVIG is comfortable and anti-slip. We love the SVIG line of products.