BOA Fit Lacing System dials in the fit, providing slip-on convenience with lace-up support Danner Dry waterproof protection, Durable, full-grain leather upper Danner Dual Layer Comfort footbed with memory foam and PU provides instant and longlasting comfort Fiberglass shank: Memory foam strobel sock offers additional cushioning underfoot, PU midsole offers shock absorption and lasting rebound Danner Caliper oil-and-slip resistant rubber outsole offers versatile indoor and outdoor traction with a low-profile 90-degree heel Electrical Hazard Protection Whether you're putting in long days in the machine shop, on a road crew or on the tarmac, sore feet make it harder to concentrate on the task at hand. The Caliper is designed for jobsite comfort and safety. The full-grain leather upper is strong and durable, but soft enough to wear right out of the box. The boot is constructed with four layers of cushioning underfoot to give you maximum comfort from clock-in to clock-out.