SYK /sɪk/: adjective for cool, excellent or rad. The SYK™ fillet series is not your grand-daddy's fillet knife. TRUE set out to design a new standard in fillet knives that are an extension of your personality and angling lifestyle, just like your fishing apparel, rods, and watercraft. The SYK fillet knife designs were inspired by the vibrant colors of the Yellowfin tuna, so they are unapologetically bold and proud making them distinct among the sea of fillet knives on the market and ideal for both freshwater and saltwater use.