This cabinet was built between 1968 and 1969, as indicated by the "Drip-Edge" trim on the front panel. On this particular example, Fender did not add any Velcro to secure the front panel, so it comes off easily—which actually benefits sound quality, during use.
Functionally, the Vibratone acts as a speaker cabinet that pairs with your amplifier, producing a sound most similar to a rich, swirling chorus effect. The original footswitch controls the fast/slow speeds, as well as turning the cabinet off. It’s important to note that turning the cabinet off while your amp is still connected can be unsafe, as running an amp without a proper load can damage the output transformer.
Overall, this piece delivers fantastic tone and classic vibe!