75 cm in diameter, which is the standard large exercise ball size and the one that fits most adults. One size covers the line, and it is the size usually chosen for sitting on at a desk as well as for training on the floor.

Yes. The cover is 100% cotton, removable and machine-washable. Take it off the ball, wash it, and put it back on. It is the feature that keeps a ball used as a desk chair looking right after a year of daily contact.

200 kg, which is 441 lb. It is a high figure for an exercise ball and the same rating carried by the HedgeHock and the Coreformer. The ball's own weight is 1 kg.

A PVC core inside a 100% cotton cover, with an artificial leather grip band around the outside. The core holds the air and the shape, the cover handles contact and washing, and the band gives you a handhold.

Assembly is listed as required, which on a ball means inflating it to size before first use. Beyond that there is nothing to build, fix or connect. If you do not already have a pump for a 75 cm ball, sort one out before the delivery arrives.

Active sitting is one of the named uses for it, and at 75 cm the ball is the right size for most adults to sit on with their feet flat. How long anyone wants to sit on a ball in a working day is a personal call. It sits alongside yoga, Pilates, functional training and stretching as the fifth thing people buy a VivaBall for, and it is the use that asks most of the washable cover. The HedgeHock is the alternative in the range if you want a seat that stays where you leave it.

One year from the date of first shipment, extended to two years on all components by registering the product within the first year of purchase. Spare parts carry ninety days, and the cover applies to private and commercial use alike.

Yoga, Pilates, functional training and stretching are the four named uses, and a 75 cm ball is large enough for all of them. The four ask the same curve for different things, since stretching lies back over the ball, Pilates work kneels or lies along it, functional training moves the body against it from the floor, and seated work wants both feet flat and the thighs level. One ball covers all four uses at that diameter.

The cover and the band. A standard gym ball is bare PVC with nothing to hold and no way to clean it beyond wiping it down; the VivaBall wraps the same kind of core in a washable cotton cover and adds an artificial leather grip band. Both changes are aimed at a ball that lives in a room people use for other things.

With a standard exercise ball pump, up to the 75 cm diameter the ball is built at. The VivaBall ships flat and assembly is required, so inflating it is the first job: bring it up to size, leave it an hour to settle, then top it back to 75 cm before anyone sits on it. The core is premium PVC and a ball in daily use loses a little pressure over the weeks, so keeping a pump with it saves borrowing one. The 100 percent cotton cover comes off for machine washing once the ball is at size, and the 200 kg (441 lb) maximum user weight applies at the full 75 cm.

1 kg. The ball is carried one-handed by the artificial leather grip band and takes up 75 cm of space in a corner when it is not in use. The weight of the ball tells you nothing about what it will take: inflated, it carries a 200 kg (441 lb) user rating.

Inflate it to size at the start, keep the cover clean, and there is nothing else to do to it. No frame wants tightening, no moving part wants oiling and no supply wants checking, so the two jobs the ball starts with are the two it keeps. Pressure is the one thing worth watching, so check the ball against 75 cm every few weeks and put back what it has given up, and send the cover through a machine wash whenever a busy month has earned it one.