The front of the Ultima AC can be pulled back like a drawer to reveal the water curtain. It has been made this way so that the water curtain can be easily removed for cleaning. It’s surely a unique way of accessing it as most other portable ACs do it differently. Battery Operation: Again, unlike most other portable air conditioners, the Ultima AC can be recharged and run on battery power alone. It charges via a USB-C port, which is highly convenient as it is pretty much the universal standard nowadays. The battery is claimed to last for 8 hours of continuous use, which is impressive considering the size of this device. Ultima Portable AC is ultra portable and can easily be carried around. Incredibly easy to set up. Battery operated so it doesnt require to be plugged in all the time.