C.F. Otto Müller was the German distributor of Poul Henningsen's lights. He developed his own highly functional lighting line employing a single stepped glass shade that prevented glare and was easy to clean. Called "Sistrah" (she who shines brightly) in Germany, the series was marketed under the name "Megaphos" elsewhere. ZP in the model number stands for Zug Pendel (pulling pendular) and as with Henningsen's lighting, the number corresponds to the overall diameter of the shade.