After opening up and cleaning all of the little parts inside the mechanism, I swapped out the guts of my existing XJ600 fuel tank gas cap into this one and let me tell you; my gas tank looks WAY better. This was probably the best $8 I've spent this year on updating my XJ just a little bit.
Product was as described (no key) and one of the wafers inside the tumbler was goobered but it was all easily remedied by switching my XJ600 tumbler wafers and a good cleaning.