Rosendahl Large Boning Knife, Flexible, 7.5 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 large 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.