Two keys appear to be permanently linked and, no matter how you look at it, there is seemingly no solution to unlocking them. However, as a highly popular puzzle since its creation during the 19th century puzzle craze, the keys are in fact separable.
The hint is "Enlarge".
Age : 10+
Package : original packaging
Level : 1
Size : 4 1/2 in x 1 1/8 in x 1 in / 11.5 cm x 2.9 cm x 2.7 cm