Impressions Moonshine Jock Coral S/M from Male Power Underwear. Leave a lasting impression in the Impressions Moonshine. This sexy jock brief has a front pouch and open back for maximum comfort and exposure. Keep them coming back for more in this sultry brief. If you are looking for some mens backless underwear, this is the perfect style for you. Men sizes small to medium. Waist sizes 28 inches to 34 inches.