The package looks like this. This is the Raspberry Pi Pico 2 W. The dimensions are approximately 21mm x 51mm. To get an idea of the size, hold it between your fingers like this. The ...

you also get example GATT server and client application codebases to use in your projects, designed to work with the commonly available Pi Pico W!

Those are the flagship Pi with the most horsepower and connectivity options, the Zero series with a smaller form factor and fewer ports with lower specs ... the $7 Raspberry Pi Pico 2 W.

That means there are a lot of options to choose from, but unless you have a very specific need in mind, there’s one name you ...