Zero Tolerance 0452CF Flipper Folding Knife Carbon Fiber (4.1" Satin) Sinkevich ZT - Model 0452CFZero Tolerance 0452CF Flipper Folding Knife Carbon Fiber (Sinkevich) The original Zero Tolerance 0454 was an award winning collaboration between ZT and custom knife designer Dmitry Sinkevich. But it was also a VERY Limited Edition knife. To make this amazing knife more readily available, ZT created a version based on the originals streamlined form and high performance function. From office to outdoors, the 0452CF is ready to go wherever you're ready