Thank you for viewing. GIVI Motorcycle Rear Box Monolock 47L SIMPLY Unpainted Black Red Lens With backrest for tandem use Main unit, 2 keys Size (outer dimensions): Depth 425x Width 555x Height 325mm It has a capacity of 47 liters, so you can store a lot of items. The backrest is made of a soft material and is gentle on the back. I think you can enjoy tandem riding. I usually store it indoors and only install it when I use it. Please let me know if you need a base. I have used it for several years, but there are no major scratches. Please check the photos. Thank you.