What’s inside an oscillator module?

[Circlotron]

Anyone know what’s inside one of these tiny 4MHz  4mm x 7mm oscillator modules? Roughly what freq crystal and how long a divider chain? And how accurate is a random Chinese one likely to be? No dire need to know these things, just wondering.

[james_s]

I saw a youtube video some time back of someone dissecting one.

I think this was it:

From my limited experience, accuracy is pretty good on the ones I've used, comparable to any other typical crystal. The temperature compensated ones are substantially better.