Coasters can be purchased as single piece or sets. Each set comes with 4 coasters and each coaster is 4"x4". All slate coasters are laser engraved and the design may vary slightly from the picture. Each piece of slate is unique and may vary piece to piece. All designs are unique and created by Abington Faire. Each coaster comes with felt pads on the bottom to protect your table and allow you to stack them and prevent scratching or marring when stacking.