Gravitron Plus S5GRV

The Nautilus Nitro Plus Gravitron Chin/Dip provides a proper biomechanical movement pattern and the kneeling design reduces height and enhances user comfort. The Nautilus Nitro Plus line is a compact, durable, and ergonomic line of variable resistance selectorized strength machines designed to adapt to the way the body moves for more efficient performance and quicker results. Nautilus Nitro Plus equipment utilizes Optimal Strength Curve Technology, which ensures smooth resistance and correct muscle recruitment through the entire movement, as well as dynamically matches the user's strength curve through a patented four-bar linkage mechanism and converging axis movements. The partially-shielded weight stacks are seat-accessible and bright yellow adjustment knobs are easy to identify and user-friendly. The Nautilus Nitro Pus line offers the same functionality and technology as the Nautilus Nitro machines, but its upgraded appearance and special enhancements will definitely attract attention. A Nautilus Nitro Plus Gravitron Chin/Dip is, and can best be described as follows: An Assisted Chin Dip is a selectorized piece of exercise equipment that is designed to assist in performing chin up and dip exercises by using a pin-selected counterweight to reduce the total effort required by the user to perform the exercise. The user kneels on a pad and chooses either handles above them (for an assisted chin-up exercise) or handles at their sides (for an assisted tricep dip exercise.) Most machines also incorporate a fold-away knee pad if the user prefers to perform a more difficult, unassisted exercise.

Buying guide

Best GHD for a Home Gym — July 2026

What is a Machine?

What a strength machine is

A strength machine guides the resistance along a fixed path so you can train a movement safely, often without a spotter. The main types: selectorized (pick weight with a pin), plate-loaded (add your own plates for a heavier ceiling and better feel), and functional trainers / cable machines (adjustable pulleys for dozens of exercises).

Machines vs. free weights

Machines shine for isolation, safety, and high-rep hypertrophy, and for training hard alone. Free weights build more stabilizer strength and carry over better to sport. Most well-rounded home gyms use a rack and barbell as the core and add one machine — often a cable/functional trainer or a lat-pulldown/row — to fill the gaps.

The sub-types worth knowing

“Machines” covers several categories that barely compete with each other: GHDs for hamstring and posterior-chain work, belt squats for loading the legs without the bar on your back, leg press / hack squat combos for heavy quad volume, reverse hypers for posterior-chain work and lower-back decompression, cable towers and functional trainers for pulling movements, and row machines. Pick the one that fills a gap in what your rack and barbell already do. Almost nobody needs two.

Space and standalone vs. rack-mounted

Most of these come in a standalone version and a cheaper rack-attachment version. The attachment saves floor space and money, but often gives up stability or range of motion — a tradeoff worth checking on the specific product rather than assuming, since it varies a lot between designs.

A note on ratings

Machine listings frequently show a manufacturer’s own on-site rating, which runs high (4.7–5.0 is typical) and sometimes pools reviews across a whole product family rather than the exact configuration you’re buying. Where we have independent hands-on coverage, our summaries anchor to that instead, and say so on the product page.