Vroom Vroom, Beep Beep. A diaper stacker is a great way to organize the natural clutter around a baby’s changing area, while also adding a dash of style and fun to the room. Our Transportation Diaper Stacker is a great addition to any baby’s room and features fire trucks, police cars, tow trucks, semi trucks and more in vibrant shades of red, blue, green, white, and black, with a blue and white checkered top. A great compliment to our transportation bedding collections.