Engineered For Midrange Warmth in Moderately Cold Conditions. See Technology section below for more details. These men's heavyweight bibs hold their own through wind, light rain, and several seasons of hard work. The overalls are made with our rugged firm-hand duck, the most durable canvas out there. They have a smooth quilted lining from the waist down, with ankle-to-thigh leg zips for quick ventilation.