I am afraid the comment on lockdown mode and the lock needing a locksmith to release it is true. I got the same advice from Tech support at Kensington Europe. They will apparently refund you and replace the lock. I prefer not to use the lock because of this crazy feature! I am most annoyed as this does indeed seem stupid and is not what they advertise. However check it out if you are still unsure but do so before you get caught out.
I read the review about the red dot appearing "in the lock" when tampered with. I cannot even see a place where a red dot would appear. That would make no sense anyway. Almost any place which would require a lock would not be a good place to have to leave your laptop and wait for a locksmith. A moderator should cut that post. This lock seems great for the math tutoring center at the local University; or at any place where you can keep the honest people honest. Most kensington lock connections are a plastic part of the housing anyway. If someone wanted your computer that bad she would have it anyway.
Pros:Good security features, cable length provides allowance for larger fixtures.
Cons:If tampered with, the unit enters lockdown mode, a red dot appears in the lock, and the key will not fit. The only option for resetting or removing is to contact a professional locksmith (confirmed by Kensington). This would be extremely frustrating if sitting in the airport or at a customer site.
Cons:The third time I used this lock the combination dials stopped working. Since this happened while it was locked in my laptop to a desk in a hotel room I was quite upset. After 30 minutes of desperately trying to get the dials to turn and twisting the lock around it came free of the laptop (without unlocking). So, not only does this lock not work, it does not protect the laptop from theft. I do not recommend this product.
Cons:Make sure you check to see if it is compatible with your laptop. I bought it since I read that it is compatible with 99% of laptops, but found that I was wrong. It doesn't work with the Inspiron 1521. I have to return it now.