Google's Pixelbook comes with a big trackpad, a touchscreen, and (obviously) a keyboard. If that's not enough input for you, there's the Pixelbook Pen for an additional $100. This fancy stylus lets you write, draw, and access Google Assistant. One thing it can't do is dock inside the computer. Recognizing the obvious storage conundrum here, Google has decided to send out pen loops to all previous purchasers.
If you bought a Pixelbook, head over to the promotional site to get your free loop. This is for anyone who bought the Pixelbook, not the Pen in particular. The assumption is you'll only want the loop if you also have the Pen, I suppose. To sign up, input your 10-digit Pixelbook serial number and shipping information.
The loop attaches to the Pixelbook with an adhesive, providing a handy spot to store the pen. It just looks like a small fabric tube on the edge of the laptop. Presumably, this will come with future Pixelbook shipments.