If you purchase this item with other products, I will sell it for 400 yen, so please let me know. This is a compact and inexpensive knife sharpener! It may look like a small toy, but this knife sharpener does a great job! We have received positive feedback from customers, such as "It's small, but amazing! The sharpness is the best." All knife sharpeners basically sharpen by placing the blade against a V-shaped whetstone and pulling it across. The size of the V-shaped whetstone where the blade makes contact doesn't change much whether the body is large or small. Therefore, even though it's this small, it works just as well as a larger knife sharpener and will restore the sharpness of your knives. You'll see that you don't need to spend a lot of money on a knife sharpener to get a good result! This is a very compact knife sharpener, but it can do both coarse and fine sharpening! To use it, simply place the knife blade between the whetstones and pull it through a few times. After coarse sharpening, flip the sharpener over and use the white whetstone for fine sharpening. The size is 2.4cm x 5.8cm x 7.2cm, so it won't take up much storage space. This size, this price, and with fine sharpening included, this is a highly recommended product!