Cut a circle out of the sheet protector approximately 1"-2" larger than the hole of the cardboard roll. Attach the plastic to the end of the roll with a rubber band. You can help the plastic fit around the roll by making small cuts around the plastic. Repeat with the second roll.
On the bottom (non-plastic-covered) end of each roll, punch two holes across from each other. Line up the holes and attach the rolls together with a rubber band (Image 1). Cut a length of yarn, twine or string and tie the ends through the holes on the outer edges, creating a neck strap (Image 2). Tie a smaller piece of yarn, twine or string through the two inner holes to secure the rolls together.