Rosendahl Medium All-Purpose Knife, Flexible, 6.25 inches. The Rosendahl's Professional Knives were developed in consultation with professional chefs. The designer put a lot of emphasis on harmonizing clean lines of design with the value of a good, professional tool. Rosendahl Medium knives are put through a forging process. This produces a knife with superior strength and durability. The hand grip is specially weighted for perfect balance. Rosendahl large knives are put through a forging process, making it a strong knife with superior durability.