Bought these and never used them. Great quality brand! From Graf Lantz: Coasters That Work Wool is the most hydrophilic of all-natural fibers, absorbing as much as 30% of its weight without feeling wet. Our traditional Bierfilzl ("Beer Felt") are the highest quality German Merino wool coasters on the market today. Their clean and minimal execution offers an unexpected textural and refined modern heritage element to any home decor. Set includes 4 handmade heavy-duty 5mm thick mixed-color Merino wool coasters to provide extra surface protection. Includes 4 coasters in Loden Green, Pistachio, Ash Brown, and Chocolate. 5mm Merino Wool Felt Includes 4 coasters Overall: 4" H x 4" W Sustainable, biodegradable, and renewable Odor, stain, heat, and dirt resistant Oeko-Tex® Certified Made in USA