The Precor EFX? 5.23 Elliptical delivers a solid cardio and muscle-toning workout. The Precor EFX 5.23 Elliptical Fitness Crosstrainer? provides smooth, natural, low-impact workouts that help you get results. And with its smaller size, manually adjustable, 3-position CrossRamp? technology and the right amount of workouts, the Precor 5.23 is convenience defined.