Check the listing for details. Precor EFX 5.17i Rear Drive Elliptical Trainer. Condition: Used. Listed at 325.00 USD. The Precor EFX 5.17i Rear Drive Elliptical Trainer is a high-quality elliptical machine designed for gym and training purposes. With its innovative rear drive system, this elliptical trainer provides a smooth and efficient workout experience. The Precor brand is known for producing reliable and durable fitness equipment, making the EFX 5.17i a popular choice among fitness enthusiasts looking to improve their cardio fitness. Whether you are a beginner or an experienced athlete, this elliptical trainer offers a variety of workout options to help you achieve your fitness goals.