The Engineer Mid in Old Crazy Black, the original in a new edition. Black Cow leather Leather lining Functional back zipper Vibram sole Round toe Heel height 3,5 cm Shaft height 40 cm Handmade in Spain An updated icon. The Engineer Mid boot is handmade at the Primeboots factory in Spain with quality cow leather and durable vibram sole. Crafted - made to last. These boots are true to size, order the size that you normally have.