Built with a 2:1 resistance ratio, they deliver smooth, controlled movement for presses, rows, curls, and countless functional exercises. With multiple lock points, you can fine-tune the arm angles to target every muscle group, while also allowing you to get a greater stretch on the muscles by adjusting the pivot arms to wider settings. Whether you’re simulating machine-style lifts or working through more natural movement patterns, the pivot arms make every workout more dynamic and customizable—all included standard with the K2S Stealth.

The K2S Stealth is powered by dual selectorized weight stacks, giving you smooth and consistent resistance for all your training. What sets it apart is that the top and bottom center pulleys draw from both stacks at a true 1:1 ratio—so when you load 100 lbs, it feels exactly like 100 lbs. This makes the K2S perfect for heavy, compound lifts like lat pulldowns and low rows, where full weight transfer and authentic resistance matter most.

The K2S Stealth adapts to your training level from day one. Choose the stack weight that fits your goals—available in 165 lb, 198 lb, or 264 lb per side—so you’re not locked into a one-size-fits-all setup. Every stack also comes standard with integrated plate horns, allowing you to top-load Olympic plates for even greater resistance when you’re ready to push beyond the selectorized limits. This means your machine can grow with you over time, whether you’re just starting your strength journey or chasing a new PR.

The K2S Stealth gives you the choice of nylon or upgraded aluminum pulleys, so you can tailor the machine to your budget and preferences. Both options deliver a staggering 80 inches of cable travel—far more than most all-in-one trainers—allowing for full stretches on chest flyes, deep rows, and overhead pulldowns without restriction. The result is smoother motion, greater range of motion, and more effective muscle engagement across every exercise. Whether you stick with the durable nylon pulleys or upgrade to aluminum for maximum longevity and precision, the K2S ensures whisper-smooth performance rep after rep.

These fully articulating arms move across three planes with multiple lock points, letting you replicate almost any leverage-style exercise from a commercial gym. Beyond presses and rows, they also unlock a unique dual leg press function: perform a vertical press on the Smith bar for maximum load or a seated press off the stacks for a joint-friendly variation. Compatible with most 2″–3″ rack systems, the 3D Jammer Arms add variety, intensity, and long-term value—making them one of the most versatile upgrades available.

The K2S Stealth comes standard with professional-grade J-cups and spotter arms to elevate your free-weight training. The J-hooks feature thick UHMW protective padding to safeguard your barbell’s knurling, while the heavy-duty spotter arms come lined on top and are ready to safely catch the bar if you miss a rep. These aren’t entry-level parts—they’re durable, gym-quality attachments built to withstand serious training. (Many competitors charge extra for upgraded J-cups and safeties, but with the K2S Stealth they’re included as standard.)