Replacement top front knife for Muller Martini 360 361 390 370 380 400 459 HCHC book trimmers. We offer the best quality cutter knives for these cutters in several styles / locations, including these top front and top side knives for the left and right sides. These durable Jayhawk Diamond Cut replacement blades are manufactured from solid D2 tool steel. Each High Carbon High Chrome (HCHC) knife is precise, thoroughly hardened, and possesses extremely wear-resistant properties. This type of high quality knife is used solely in bed knives for three knife trimmers. These Jayhawk Diamond Cut blades are manufactured to not just meet, but to exceed OEM specifications, ensuring extreme precision and longevity.