This is a placeholder topic for “9V to Barrel Jack Adapter V2” comments.
This is the second version of the 9V to Barrel Jack Adapter. In this version the material for the 9V battery jack is hard plastic, which makes it easier to connect and disconnect.Read more
What is the inside dimension of this product? It doesnt say if it is 2.1 or 2.5mm
It mentions 5.5x2.1mm(so a 2.1mm inside pin) about halfway down the description(that’s where you can usually find the juicy features/specifications).
This one is really a life saver when one needs to power up an Arduino with a 9V battery.