Best Grandpa Ever Coaster Funny Father's Day Gift 4 Pack Round Rubber Drink Cup Coasters Black The best Father's Day gift. This gag gift for Grandpa or Dad alike is sure to bring a smile. This 4 pack includes 4 coasters with the design pictured. Premium full color sublimation printing creates vibrant and long lasting colors. 100% polyester top and non-slip black rubber base feels just like a mousepad. Absorbant material protects surfaces from cup rings. Coasters give your table, counter top, or office desk some style and protection.