what are the QueuedPool parameters ?

[MahdiZareie]

thanks for nice package, I couldn't find any document explaining QueuedPool parameters .
can you help me with that ?
some of parameters like create and max_size are don't need more explain but I need some descriptions about the followings:
max_overflow , timeout, recycle, stale
I'm creating a django app and I'm going to publish it so I need to explain what are these settings
thanks in advance