Sferoflex SF1578 eyeglasses pair the brand's patented flex-hinge comfort with a butterfly-shaped acetate frame, offering a lightweight option for everyday prescription wear. Key attributes: Black | Nero | Acetate | Lightweight construction | Durable frame | Patented flex hinges for added comfort | Demo lenses included — replaceable with prescription lenses | Prescription-ready | Butterfly (cat-eye) silhouette | Full-rim frame | Metal temple details | Dimensions & fit: Size 53: lens width 53 mm · bridge 16 mm · temple 140 mm · height 41 mm | Size 55: lens width 55 mm · bridge 16 mm · temple 140 mm · height 43 mm | Regular fit | High‑bridge fit | Composition & care: Acetate | Metal | Wipe lenses with a microfiber cloth. Clean the frame with a soft cloth; avoid abrasive cleaners and excessive heat.