Sportula Products 7015743 Arkansas Razorbacks Boaster Coaster by SPORTULA PRODUCTS. $23.15. Set of Four. Heavy-duty stainless steel. Strong cork backer. Unique laser-cut design. Boasters are a set of 4 Heavy-Duty Coasters made from stainless steel and have a strong cork backer. They are the perfect compliment to its Sportula counterpart.