Comfort That Works Overtime. 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.