Advertised as X-Wide but is a full 3/8 inch narrower than the previous New Balance Minimus MX20v4 of the same size. many different models including: many pairs MT10MT20MX007MRMX20v4 (favorite, durable and wide) There were problems with outsole separation in the first model year, but since then the only big problem for me has been outsole wear. The v7 shoes are noticeably narrower than their predecessors and I was disappointed that the Minimus Prevail was as well. Compared to other Minimus models I found them heavily lined with straps and not at all like barefoot style Minimus shoes. Both the new Prevail (black boot/sole) and old MX20v4 (green/grey) shown in the images are 13 2E (the Prevail was "X-Wide" on Revain but only 2E). As you can see from the pictures, the Prevail is almost 15mm narrower at the toe (too narrow for me), about 10mm wider at the heel and has significantly thicker padding in the heel. With thick cushioning and no tight-fitting heel, the Prevail feels more like a regular running shoe than a Minimus shoe. Finally, the Vibram sole of the new Minimus Prevail is soft - almost like a soft rubber outsole. I believe it will wear out much quicker than previous Minimus models.