Will it work with my treadmill?

Probably. Belt Control doesn't go by model name — when you connect, it asks your treadmill what it can do and adapts to the answer.

That matters more than it sounds. WalkingPads sold under the same model name have shipped with different parts inside in different years, and the X21 appears in KingSmith's own catalogue in two versions. A list organised by model name would be wrong for someone. Asking the treadmill directly works for everyone.

So the useful question isn't what your pad is called. It's which of four Bluetooth "languages" it speaks — and you don't need to know the answer, because the app works it out for you.

The four families

A dash means the treadmill doesn't report that number, so the app shows a dash instead of making one up.

For pads in the last row, Belt Control can find and identify them but can't control them yet. If that's yours, you can help change that — see the bottom of this page.

Why some pads have a Pause button and others don't

Pausing isn't the same as stopping. When you pause, the treadmill holds on to your walk, so when you start again it picks up where you left off instead of starting a new session from zero.

Not every treadmill can do it, and there's no way to ask one in advance, so Belt Control tries it and watches what happens. If your pad turns the request down, the app stops the belt properly, tells you so, and hides the Pause button for the rest of the session. The one thing it must never do is say Paused while the belt is still moving.

Older pads in the Classic family have no pause at all — not in Belt Control, and not in the manufacturer's own app either. Stop is the only option there.

Why some calories say "rough estimate"

Because on those pads they are one. The treadmill doesn't measure how hard you're working. It multiplies your distance by a fixed number and calls the result calories, knowing nothing about your weight or your pace.

Belt Control still shows that figure, but marks it and leaves it out of your totals. Quietly adding up a number we don't trust would make every total wrong, and that's worse than leaving a gap.

Your browser matters more than your treadmill

This is what usually trips people up. Belt Control connects to your treadmill over Bluetooth straight from the web page, and not every browser can do that.

There's no way around the iPhone one. On an iPhone or iPad every browser — Chrome and Firefox included — is really Safari underneath, so installing a different one changes nothing. Use a computer or an Android device instead. Most of these treadmills live under a desk with a computer already on it, which is the setup Belt Control is built around.

If your pad isn't listed

Try it anyway. The lists above are the models we've seen, not the only ones that work. The app asks your treadmill directly, so an unlisted pad from a known family should just work.

If it doesn't connect, the app keeps a record of what it tried and what your treadmill said back, and Send feedback attaches that record to an email. That record is what makes it possible to add support for a pad nobody has seen before.