I am a student living in a dorm situation and so wanted some basic protection for my lap top computer. I purchased the defcon cl because it was inexpensive, widely availible, and easy to use. Unfortunately, it has one major drawback, occasionally it decides to change the number combinationss which unlock it. I went to the company website and they suggested trying the numbers immediately around the combination and if that failed trying all the number combinations possible (there are 10,000). Several hours, one blister, and 1787 combinations later, I got frustrated and used a jewelers saw to cut through the connection to my computer (this solution took only five minutes). I would not suggest this lock to anyone who lacks the patience to try trial and error experimentation until they reach the correct combination, nor anyone attending a school with a metalsmithing program.