Both V-10 and TE cylinders and keys are patented, protecting them from unauthorized duplication. The V-10 and TE incorporates the same key control, physical security and protection that has made ASSA the leading High Security manufacturer in the world today. ASSA 6000 High Security Deadbolt Features • ASSA UL Listed High Security Cylinders • Patented Key Blanks for Absolute Key Control • 1” Throw Hardened Steel Bolt • Tapered, Free Spinning Wrench Resistant Cylinder Guard Rings • K Aircraf