Sheetrock Pro Series 6" High Carbon Joint Knife 340030 Design and functionality based on USG Sheetrock Matrix line of knives at a new economical price. New features including heavier back end for perfect balance, larger nail setter tip, improved soft grip handle for ultimate comfort, tapered neck for more control and less fatigue. Developed by professional drywallers for professional drywallers. Carbon steel blade for superior strength and durability The best feeling taping knives in the business at a price point that makes them affordable.