Size* Outer dia is 4.3", inner dia is 3.94", and thickness is 0.63", not too big to jeopardize the whole setting; not too small to affect functionality.fits most types of bottles/cups/mugs/tumblers Olen* Every table setting needs a few coasters. what makes Olen stand out are the features like water absorption, heat insulation and noise reduction. Its design blends in with any style you like. Material* Premium felt pad is resilient and soft, offering water absorption and heat insulation; natural wood pattern allows Olen to go with any style while conserving its identity. Design* Unique "sandwich structure", two pieces of felt are neatly inlaid in solid wood. when placed on a table, the top felt is absorbent and heat insulating, and the bottom felt is to isolate the noise of the table and coasters while making it anti-slippery. Holder-free Concept* Like every other coaster from S1EGAN, Olen is designed holderless so it can be stacked up on one another easily when set aside. Last bit, A Perfect Gift* A delicate and practical gift for housewarming, holidays, parties, and occasions. OLEN Felt sandwich design with a natural wood frame. Why did we design olen? The idea originated from our best selling coaster, PAN, which utilizes cork as the main material, offering water absorption, heat insulation, and anti-slippery features. We thought about utilizing felt the same way we did with cork, but the colour of felt doesn't fit with acacia wood, and the felt ring doesn't seem to offer the same support as the cork ring. Instead, with two pieces of felt of the same size inlaid in the solid wood from both sides, olen is able to offer excellent support forces. and finally, when that dark grey touch of felt meets the walnut colour of the solid wood, everything just felt so right...