Common Chinese brand XXOFF.
The products of brand XXOFF include: concentric knot, ring chain, twist chain, magnetic bracelet, concentric lock, gear chain, titanium steel bracelet, lover's lock, black ceramic necklace, silver glitter, sunstone, silver necklace, lucky stone, wishing stone, titanium steel ring, titanium steel bracelet, cross line, combination chain, silver sleeve chain, silver pair ring, etc.
Silver jewelry should generally be stamped with the English abbreviation of silver ("S" or "Sterling"). The mark of Standard Silver is S925, and that of Full Silver is S990.
Do you want to see the mark on the XXOFF to know whether it is pure silver