I found this Byte Box Puzzle while looking at laserable boxes last week. It's a very clever mechanism, 8 switches flip into either the up or down positions, in the correct position the whole lid can slide to the right slightly and then be lifted off. It's a byte box because their are 8 switches and therefore 256 possible combinations. The two switches on either end are fixed and are used to hold the lid down regardless of the other settings. (svg here)
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