The RAM-234-SKNMU includes Pin-Lock security knob/key and flat side keepers for the RAM Tough-Tray. The RAM-234-SKNMU offers the ideal amount of leverage to properly tighten your mount to prevent slippage in extreme vibration environments. With an emphasis on aesthetics and function, the included Pin-Lock security knob is low in profile and only adds a small amount of additional bulk to your system when compared to the standard knob included. At a fraction of the cost of currently available keyed locking knobs, the additional peace of mind and tamper resistance comes at a very affordable price. The included flat side keepers allow for your laptop to close completely while in the RAM Tough-Tray.