Nitori's super-insulating and cooling bottles, 500ml and 750ml. It seems that they no longer sell anything other than the 900ml size. I purchased the 500ml bottle online from Nitori last February. I bought the 750ml bottle later. I originally used a mont-bell insulated bottle for mountain climbing and planned to use these as a backup, but I haven't had a chance to use them, so I'm selling them. Therefore, both are new and unused. I have never used them outside. Of course, I haven't used them indoors either. They are new and unused, but after purchase, I opened the boxes and stored them in a dark place for a while, so there might be some minor scratches or dust. They are almost new, but please consider them as used items. The original boxes, bags, and instruction manuals are all included as shown in the photos. Instant purchase is welcome. I will ship them as quickly as possible, aiming to ship them the day after purchase. Thank you.