It means the metal is 92.5% pure silver, the standard sterling alloy. The remaining 7.5% is usually copper, which adds strength.

Will the plating wear off?

Plating sits on the surface, so it thins where the necklace rubs against skin or clothing. Take it off before showering, swimming or heavy sweating to slow that down.

Can I wear it in the shower or pool?

Better not. Water, soap, chlorine and salt speed up tarnish and plating wear. Put it on last and take it off first.

Wipe with a soft dry cloth after wear. For tarnish, use a silver polishing cloth; skip abrasive dips on plated pieces, which can strip the finish.

Is it good for sensitive skin?

Sterling silver is a safer bet than nickel-heavy costume jewelry for most people. If you react to the plating or the copper alloy, a pure fine-silver piece is safer.