- RAINBOW. WILLOW00-EDB. THE WILLOW DOUBLE LAYER ARCH SUPPORT PREMIER LEATHER WITH INSET DOUBLE BRAIDED THREE QUARTERS MEDIUM STRAP. The Willow is made using the double Layer foot bed, giving an extra layer of midsole that starts at the arch and rises towards the heel. Giving those with a higher arch more support and extra comfort. The double layer midsole is made to break down 10 percent under your foot giving the exact mold to your individual foot.