This boxed set of 6 acrylic coated cork backed drink coasters were manufactured by Jason Products Ltd. in New Zealand. The design called Black Vase is an exclusive for Jason by Australian artist Ken Done. Each coaster is 3.75 x 4.50 inches. They have been used but only one shows evidence of it. It has a small black mark on the front (see pic) and some ink marks on the cork back. The coasters are signed Ken Done.
If you are not familiar with Ken Done, I recommend his very interesting and colorful website, www.kendone.com. Every time I run into something he designed, I am amazed he is not as greatly recognized in North America as he is in Australia where he is a household name. His works are uplifting, like listening to bouncy music or the sun suddenly emerging from behind a cloud. He has had many one man shows in major cities around the world including the USA.