It's not what it seems. According to Kensington, there is no master key for these locks. They work correctly, but the master key is not possible.
Secure Your Notebook with Kensington 64343 MicroSaver DS Keyed Computer Lock
11 Review
Secure Your Laptop with the π Kensington K64638WW ClickSafe Keyed Twin Laptop Lock
12 Review
π Sturdy Combination Lock for Laptop and Notebook Computers: 6mm Thick Black Security Cable Included (6ft Long)
9 Review
Kensington Microsaver Universal Computer Key Lock and Cable Security System 64162a for Desktops
9 Review
π» Get Amazing Video Quality with Logitech HD Pro Webcam C920 (Discontinued Edition)
83 Review
Logitech HD Webcam C270: Crisp 720p Widescreen Video Calling & Recording (960-000694), Lightweight and Portable at 3.15 lb.
192 Review
Enhance Your Visual Experience with Logitech C260 Webcam
78 Review
Sennheiser PC 8 2 Cancelling Microphone
71 Review