1. Bears Rear Box (Outer dimensions) L 510 x W 380 x H 370 (mm) (Inner dimensions) L 470 x W 350 x H 360 (mm) Includes fixing belt and key. The width is about the size of a motorcycle seat, and it's vertically long. I bought it in white, but I changed it to gray myself. However, I couldn't spray the bottom, but you probably won't notice it when it's installed. It's large, but not wide, so it fits snugly on a motorcycle (I ride a Tricity). I think it's big enough to hold large purchases from Costco, etc. You might not need the fixing belt, but if you're worried about just tightening the screws, you can secure it with the belt to the motorcycle base or the hooks on the rear box to prevent it from coming off. With the optional fixing belt, box, and shipping, it cost 39,468 yen including tax. 2. Honda Rear Box Purchased from Amazon, please check. There's a trick to opening the box with the key; you need to insert the key halfway and turn it. If you insert it all the way, it won't open properly, so please be careful. Purchased for about 12,000 yen. Both have been used for less than a year and are not broken. If they don't sell after a while, I will list them on Yahoo Auctions. Shipping is also expensive, so I may not be able to offer discounts or reply to comments often because I'm busy. Please check the photos or the website name shown in the photos. Also, you probably know that you will need a separate base and screws to attach the rear box. Please attach this rear box to a base that fits your motorcycle. In my case, it wasn't a Tricity-specific rear box, so I made holes in the bottom of the rear box and tightened it with screws to fit the base.