The Aqualis series expansion tanks are equipped with a borosilicate glass tube, which, in contrast to the acrylic glass commonly used for tube expansion tanks, offers very high hardness and scratch resistance, very low thermal expansion, and excellent chemical and thermal resistance. The glass tube has an outer diameter of 75 mm and a wall thickness of 5 mm. The base and lid of the Aqualis series are made of Delrin, and the lid and base are connected by a nickel-plated brass tube. The Aqualis base for pump adapters is equipped with connection flanges on the underside and can only be used with a compatible Aqua Computer pump adapter. Optionally, up to two lighting modules can be mounted in two G1/4 threads. An optical highlight is the integrated water column effect. When the return line is connected to the socket's inlet, water flows through the central brass tube to the lid and exits through eight openings, creating a striking visual effect, especially when combined with lighting. A thin acrylic glass plate near the bottom of the Aqualis minimizes air entry into the circuit. These items also feature an integrated acrylic glass window in the base, providing space for the installation of up to six LEDs. All variants are also available with a nanocoating that allows water to simply bead off the inside of the glass tube.