Length: 19 cm, Width: 23 cm, Thickness: 5 mm The four corners are rounded! It's a cutting mat and mousepad! Unused and stored in the back of a closet for many years! As you can see in the photos, there's some dirt, but it's on the bag! I haven't opened it, so I don't know what the contents are like, but I think they're probably undamaged! If you understand the condition, please consider purchasing! One piece is available for 350 yen!