The phrase
out of the box
implies something that is ready to use, you just have to "open the box" and you have what you need. This is in contrast to something that requires a lot of configuration.
However the phrase "thinking outside the box" is used to mean thinking thoughts in an unconstrained and innovative manner.
Another option is
off the shelf
which implies that something is ready and waiting to be used. Again there is no need to wait while it is adapted for particular use.
In the garment industry
off the peg (or off the rack)
refers to a garment you can simply collect and wear, in contrast to a bespoke, or tailor-made, garment which is made specifically for the customer.