Set sizes vary. Some listings offer multi-pair packs (examples given: 9 pairs and 6 pairs), others are two-pair sets, and many are sold as a single pair.
Yes — listings commonly describe round earrings as versatile. Many are presented as appropriate for everyday settings (office, casual outings) and also for parties or evening events; certain sizes/styles are noted as better for workplace, weekend, or statement looks.
Care instructions vary by item, but most advise spot cleaning or wiping the earrings with a soft cloth. Some listings explicitly warn not to wash certain pieces.
Hoop sizes reported include outer diameters roughly from 16 mm up to 30 mm, with some inner diameters given as 8 mm, 10 mm, or 12 mm. Studs and small round accents are typically about 5 mm to 8.5 mm; a few listings specify post lengths (~10 mm) and a post gauge around 0.8 mm.
Many listings are labeled hypoallergenic and specify materials for sensitive ears, including S925 sterling silver posts, 316L surgical steel small hoops, and hypoallergenic premium brass. One description also states the pieces are completely free of nickel and lead.