The HYLA EST is a unique water-bath filtration system, which uses ONLY water as a filter. Its concept is its method of trapping dirt, dust, and allergens in the water. The system forces the air through a water-bath. A specially designed separator separates the air from water so only clean, fresh, water-washed air is returned. This sophisticated design ensures superior air flow consistency & filtration efficiency. Excellent condition with all attachments.