The Peltier effect, that helps in cooling, requires water so as to figure . this is often why the BLAUX Portable AC comes with a 300ml cistern , which is an adequate capacity to stay the cooling process happening for an extended time. just in case the water level goes low, the tank is definitely refillable. Probably the foremost unique feature of the BLAUX Portable AC. it's a 200mAh lithium unit which will be charged via USB-C at DC5V, a bit like a smartphone. it's enough to stay the AC running at a maximum of 8 hours. Lastly, the BLAUX Portable AC has an air cleaner inside it, which is analogous in looks and size because the one found in cars. It helps filter dust particles and ionizes the air so as to neutralize contaminants which may cause allergies. The BLAUX Portable AC is certainly well worth the money .