Square Flip Image unique lenticular coasters. Flip from one image to another and back again. Most advertising tools only grab the attention of their audience for a few seconds. However, patrons will spend 45 minutes to one hour at a bar or restaurant, providing a unique opportunity for sports, travel and entertainment companies to capitalize on this captive audience. Features cork back.Item Size: 4 x 4Imprint Area: 4 x 4