The Surface Duo 2 is capable of reverse wireless charging to power the new Surface Slim Pen 2, but you’ll need to have the Surface Pen Cover to enable it. With the cover on, the Surface Slim Pen 2 magnetically attaches so you don’t have to carry it separately, and is always there when you need it.
Microsoft recommends that you use the Surface Pen Cover in conjunction with the Surface Duo 2 Bumper case. Keep in mind that as with the Surface Duo 1 Bumper, it’s designed to only attach once. So follow this guide to get it right the first time.
Attaching the Surface Pen Cover
Step 1: Open your Surface Duo 2 so that the back is facing you. Press the Pen Cover onto the right side (with the Microsoft logo). It should snap into place.
Step 2: Flip the Duo 2 so that the screens are facing you.
Step 3: Peel off the liner from the Label 2 section of the bumper revealing the adhesive step inside, then carefully place it on the top-right corner of your Duo 2. Press along the bumper to ensure good contact, then remove the numbered label.
Step 4: Peel the liner off from the Label 3 section of the bumper, and place it on the bottom-right corner of your Duo 2. Press along the bumper to ensure good contact, then remove the numbered label.
Step 5: You can now place the Surface Pen 2 on the edge of the cover. It magnetically attaches and charges as should be indicated by the LED light on the pen.
Note: The Surface Pen Cover is only compatible with the Surface Duo 2, and supports both the original Slim Pen and the Slim Pen 2.