KingSmith X21 Folding Treadmill

A double-folding running treadmill with a larger console, quick speed keys and NFC pairing. Built for regular training rather than occasional walking.

Why you'll love it

• A real training treadmill that still folds away. 1.25 HP, 7.5 mph, an 18.1 in belt, and a double fold that stores it in a closet.
• Speed on one key. Quick speed buttons jump straight to your interval pace instead of tapping up one step at a time.
• Tap to pair. NFC on the console connects your phone to the KS Fit app with a touch. Apple Watch supported.
• See your pace from the deck. Enlarged console plus the interactive light strip along the belt.

Specifications

Model TRX21F. Specifications are supplied by the manufacturer and may be updated without notice.

Frequently asked questions

Tap a question to open the answer.

X21: 7.5 mph, 243 lb, 82 lb frame. X25: 9.9 mph, 300 lb, 1.5 HP, 104 lb frame. If you run intervals above an 8-minute mile or weigh over 240 lb, the X25. Otherwise the X21 does the job for less.

They jump straight to preset speeds, so you go from a walk to your run pace in one press. Useful for intervals.

Hold your phone to the console and the KS Fit app pairs instantly, no Bluetooth menu. Your sessions then sync to the app, Apple Health and Apple Watch.

Yes. Fold the handrail down for walking mode. It's taller than a dedicated pad, so check desk clearance.

The handrail folds onto the deck and the deck folds in half, so the stored length is roughly half of the 47.6 in belt length. It fits in a closet or behind a door and rolls on large wheels.

Delivery

Free delivery to addresses in the 48 contiguous United States and the District of Columbia. Orders are dispatched within 48 hours of payment from our US warehouse and typically arrive within 2 to 6 working days. Orders ship via FedEx or UPS, and tracking is emailed on dispatch. We do not currently ship to Alaska, Hawaii or Puerto Rico.

Warranty and returns

Every X21 comes with a 12-month limited warranty covering the motor, electronic controller, main frame and console. The full terms are in our warranty policy.

Returns are accepted within 30 days of delivery in original packaging. Items delivered between 1 November and 31 December may be returned within 45 days. See our refund policy for the full terms.

Optional extended protection

You can add an extended protection plan from Consumer Priority Service (CPS), our warranty partner, when you order. It begins where the 12-month manufacturer warranty ends and can take total coverage up to six years.

• One single payment — never a monthly rate. You pay once at checkout. There is no subscription, no recurring charge and nothing to cancel later.
• 100% of parts and labor for mechanical and electrical failure, including manufacturing defects and hardware failure.
• Home and commercial use are both covered — the plan is valid whether the treadmill sits in your bedroom or in an office.
• If it cannot be repaired, it gets replaced.

Pick your term from the protection plan option shown with this product or in your cart. It is entirely optional, and the 12-month manufacturer warranty applies either way. Accidental damage is not covered by this plan.

Not quite the right fit?

Two alternatives at $699, each built for a different priority.