The designation AM 75 to 77 stands for 44 electric multiple units built between 1975 and 1979. They are also known by their nickname “Varkensneus” (“Pig's Snoot”) due to their nose design. Since each set consists of four cars, they are also being called “Quadruples”. The two inner cars are being powered on all axles and the outer ones are unpowered control cars. The trains of this series could also run in multiple with those of the AM 62 to 79 series. With a top speed of 140 km/h, they are being used for different services from suburban to InterRegio. Between 2015 and 2020, they were modernized to extend their life. 