What one actually costs to own

A powered device with a soft sleeve has three running costs: the sleeve, which wears; the lubricant, which is used up; and any part that fails, which may or may not be replaceable.

The first two are easy to plan for. The third is the one worth checking before you buy.

Replacement parts are not available for every device. Where a sleeve, strap or charger cannot be bought separately, a worn or lost part can mean replacing the whole device.

Before choosing, check whether the parts that wear are sold on their own, and what they cost today.

A fault outside the warranty then becomes a replacement purchase. A torn bonded sleeve, a worn strap or a lost power supply can each end a device that otherwise works.

It also changes what a warranty is worth, because the term matters most on a device that can be repaired.

Sleeve life depends on the material, how the sleeve is cleaned and dried, the lubricant used, and how close to the top of its fit range it is stretched. Because so much depends on the owner, a single lifespan figure is rarely meaningful.

What can be known before buying is whether a replacement sleeve is sold and what it costs. That turns an unknown into a running cost you can plan.

Before buying, ask whether the sleeve can be bought separately and what it costs today. A device with an inexpensive replaceable sleeve and a device with a bonded one are different products at the same price.

It is the cheapest question to ask and the most expensive one to skip.