Sound-absorbing boards designed to absorb sound. Size: 30cm (length) 30cm (width) 0.9cm (thickness) I purchased these about six months ago but haven't used them, so they've been in storage (no push pins or insect pins included). I recall purchasing them on Amazon for around 4000 yen for a pack of 12. I hope someone who can use them will take them. Thank you for looking.