I used this for about six months while I was employed, and it's still sharp. It seems like there are replacement blades available when it dulls. A letter opener with a strong magnet built into the back. You can fix the main body to metal doors or walls, and use it in a fixed position whenever you want. You can open thick envelopes or those with crushed corners without stress. The blade is made of durable ceramic. It can open about 5,000 envelopes. [Material] Body: ABS + Glass Fiber + POM Blade: Ceramic Built-in Magnet [Body Size] H55 x W29 x D15mm It's sold on Amazon for 909 yen. #Banana's Interior Corner Tap here! If you purchase multiple items and they are shipped together, you can get a discount on the shipping cost. Please request a combined order.