10 mm drop: due to variances created during the development and manufacturing processes, all references to 10 mm drop are approximate. Blown rubber outsole. Dual density collar foam. Medicare / HCPCS code = A5500, may be eligible for Medicare reimbursement. No-sew material application. Polyurethane insert. Synthetic/mesh upper. We are proud to be the only major company to make or assemble more than 4 million pairs of athletic footwear per year in the USA, which represents a limited portion of our US sales. Where the domestic value is at least 70%, we label our shoes Made in the USA.