Common questions.

Fill from any tap with the included pump, add the dye, then seal the valve. Add or pour out water any time to change the load — the same tool covers a wide range as you get stronger.

Each tool closes with a sealed screw valve and reinforced seams built to hold water under load. Close the valve and it stays put. If anything leaks in your first 60 days, we replace it — no questions.

The water shifts as you move, so the load is never quite where you expect. You brace, correct and stabilize on every rep — the control that carries over to sport. A fixed weight can't move, so it can't train that.

Every size lists its best-fit load range and who it's for, from youth to adult. If you're between sizes, size up — you can always run it at a lighter fill.

The tool, the fill pump and dye, and free access to the app and a guided course for your sport. Bundles ship as one complete system.

Free shipping on every order. Everything's in stock and ships in 1–2 business days. You get 60 days to try it, and if it's not for you, send it back for a full refund.

Yes — we build systems and volume pricing for squads, clubs and facilities. Tell us your roster and what you train on the Teams & coaches page.