In celebration of Einstein Year, physicists at the University of Oldenburg presented on Tuesday a refrigerator they reconstructed that was co-invented in 1926 by Albert Einstein and a former student, Leo Szilard. The so-called "People's Refrigerator," made of cement and without any moving parts, weighs about 300 kilograms (661 pounds). The patented invention was first presented at the Leipzig Trade Fair in 1928 and according to a newspaper report at the time, was triggered by the death of a family, which was poisoned by a leak in a conventional refrigerator. The Einstein refrigerator is made of inexpensive, non-moving parts, operates silently (due to the absence of a motor or compressor), and is very reliable. However, it was never put into commercial production also patents were sold to companies such as Electrolux of Sweden.