5 Eyelet Monkey Boot. Vintage Smooth leather- a retro version of our signature smooth leather with subtle grained effect and contrast base color. Heel loop. This is a Goodyear-welted product. The upper and sole are heat-sealed and sewn together, not merely glued like many footwear constructions. Dr. Martens air-cushion sole, oil and fat-resistant, good abrasion and slip resistance.