The double cylinder lamp has a special role of all Kandem lights, as well as of all Bauhaus produced/designed objects.

It represents the idea and background of the Bauhaus perfectly, almost like no other object.
Compared to the other lamps, Kandem asked to design by the Bauhaus, the double cylinder hanging light is the only true and 100% Bauhaus design and development. All other lamps had to be designed with parts, the company already had. All other lamps had quite exact guidelines, given by Kandem. In their request to the Bauhaus in 1928, they only asked for four lamps. The double-cylinder-lamp wasn`t even mentioned. The Kandem authorities decided to produce the double-cylinder-lamp, after they saw it. It was the first one, out of five lamps, introduced in August, 1928.

As reported by Hin Bredendieck, László Moholy-Nagy gave the idea to combine two cylinders of different sizes, to design a hanging lamp, that does not dazzle the eye. Moholy was traveling to Leipzig in feb. 1928, where the company Körting & Mathiesen AG (Kandem) was located and talked to the authorities himself. Marianne Brandt was with him and she did the final design after his idea and figured all the details, with the help of Helmut Schulze.
The lamp with it’s fragile glass cylinders and filigran free hanging inner cylinder reminds of Moholy’s three-dimensional “equilibrium studies”, which he developed in the preliminary course, he taught until 1928.
 
In the book "Bauhaus Lighting? Kandem Light!" published by Arnoldsche in 2003, ISBN 3-89790-181-1*,
Dr. Klaus Weber (Co-Director of the Bauhaus Archive museum in Berlin) reports on page 49:
"The double-cylinder lamp occupied a prominent position among the numerous ceiling lights developed by the Bauhaus for Körting & Mathiesen. Also developed in 1928, it is the only model with whose design the then head of the Bauhaus metal workshop, László Moholy-Nagy, was evidently directly involved. According to a statement made by Hin Bredendieck, the idea of constructing a ceiling light consisting in two glass cylinders of different sizes was a brainchild of Moholy-Nagy`s. Marianne Brandt collaborated with Helmut Schulze in making it. The astonishingly simple and efficiently functional principle on which this purist light sculpture was constructed evidently convinced the partner in Leipzig. The design ensured good distribution of the light screened off at the side by the two opaque glass cylinders and even prevented any dust deposits from forming since the lamp had no horizontal surfaces - exept for the edges of the glass cylinders and the metal parts. Secured by an airy construction, the inner cylinder seems to float. In this respect it may even be said to recall the three-dimensional "equilibrium studies" which Moholy-Nagy was developing at that time in the preliminary course he taught at the Bauhaus. Even Wilhelm Lotz, who tended to be critical, extolled the virtues of this design. He described the double-cylinder lamp as "felicitous in form":"Devoid of formalism, it is formaly elegant in a new sense. Good lighting effects with succinct form.""

So this lamp can be said to be the only lamp, which bases truly on the famous artist László Moholy-Nagy (He also gave advice to the Wagenfeld table lamp, though).
Furthermore, the lamp represents one of the few cooperations with the industry, back then, which were positive, for both, the Bauhaus, as well as the company Kandem. There is only one more example with the wallpaper company Rasch in Hannover, a few years later, that was even more profitable for the Bauhaus.
It can be said, that it was almost the first time ever, a company asked for an outside source of design, for their products, in order to have an authority in design to design mass-products for the market. From the beginning on this was a main goal, the first Bauhaus director Walter Gropius wanted to achieve, also in order to be independent of government resources and money.

In my opinion the double cylinder hanging lamp by Moholy and Brandt is the most outstanding and best example that accomplished Gropius goal.

*Additional specific information can be found on the following pages: 27, 29, 31, 33, 41, 49, 105, 160, 164, 166, 188, 203, 205, 211, 214.