Boutique Style Monogramed Disc Necklace aDs

I don’t know anything about this. I believe the engraved disc or pendant to be silver plated. No markings to say it’s silver. This has been Monogramed with ADS. This has been used any May shows sign of use. Comes three strand adjustable chain. Approx 20.25”- 24”. I’m my option this looks like a boutique item you would buy to have monogrammed in store or purchased online and made to order.