This is a "Tomo-kan" (bait container) and "Otori-kan" (live bait container). It's 38 cm wide and has some scratches, which are like badges of honor from years of use. It's a cooler box, originally purchased as an Ayu (sweetfish) cooler box. I believe it's a 2-sided vacuum type, 7 liters. The pump has two-stage pressure. I've confirmed it's working. For fire safety reasons, I cannot ship the batteries. Please check the photos for details.