Product with product code 89970221 was hard to fly chips but sharpness was bad. It may be suitable for sharpening people, but I will not use it until sharpening. On the other hand, 11077857 "SKY BLUE" had no problem in terms of sharpness, but the chip was not durable and it could not be cut after the chip flew. So, this 40465214 felt the sharpness and durability equal to or better than 11077857, but it was unexpected that levees and ridge cutting can be performed as appropriate even after the chip flew. That's why I liked this "Konomaru JIS Mow cutting chip saw weed" at my place.