This application,"crestview", instructs users on stationary cycle exercise. Various Features Of Precor Elliptical Trainers. The EFX Precor elliptical trainers are considered some of the best elliptical trainers. There are five different types of Precor elliptical trainers in the EFX series. These different EFX Precor elliptical trainers have various features. However some of the features on the different models of EFX Precor elliptical trainers can be found on all of the models. We will look at the common and different features that can be found on EFX Precor elliptical trainers.     Despite which one of the EFX Precor elliptical trainers that you select, all of them share a common theme that each machine will move harmoniously in alignment with your bodies natural movements. These machines are known for having lower impact then most Elliptical machines, which makes them very comfortable as you can exercise on them in a natural motion. Despite what type of the EFX Precor elliptical trainers you buy, all of them have this common feature, which makes even the cheapest EFX Precor elliptical trainer you select appealing.