Rubber outsole Adidas Women's Ultraboost 22 Casual Shoes are designed to provide comfort and responsiveness at every pace and distance. The PRIMEKNIT upper is made with foam around the heel to prevent small blisters. The shoes have a regular fit, a PRIMEKNIT textile upper, a soft heel fit, a linear energy push system, a BOOST midsole, and a lace-up closure. The outsole is made of rubber.