This is one of those no-brainer products that probably should have been invented a long time ago. When you finish painting a room, load up the Paint Pen and it will be in reserve for any quick touch-ups in the future.  Great for small apartments and condos where you can’t afford the room to store paint cans. I haven’t seen these in person, but it seems like these could be a great tool for artists as well.
Set of 2, $19.99