The 3 3/4 inch square coasters are made of 1/8 inch thick pearlized glass with smooth rounded edges and four rubber feet to protect furniture surfaces. The center window will hold a 2 inch by 1 inch photo, place card, or 'Thank You' tag (included). Each coaster set is beautifully packaged in a clear gift box wrapped with a white, sheer organza ribbon and bow. The frame already has a thank you card in place and ready to present to your guests as favors. Add personalized favor tags free of charge.