Most are made from PU leather (polyurethane); some models use ABS plastic (acrylonitrile butadiene styrene).
Common sizes shown in the listings include 15 × 30 cm (5.91 × 11.81 in), 9 × 6.6 cm (3.54 × 2.6 in), 31 × 16.3 cm (12.2 × 6.42 in), and 12.5 × 15 cm (4.92 × 5.91 in).
They attach in a few common ways: elastic bands that slip over the visor, clamp-style clips that grip the visor edge, or hook-and-loop tape on the back.
Listings generally describe them as suitable for most cars, SUVs and trucks, but sellers recommend measuring your sun visor before buying. One listing specifically warns they aren’t suitable for visors shorter than 12.5 inches.
Several listings state the case does not interfere with sight lines, but they also advise checking that the case is securely fastened and not loose before driving.
Many are PU leather and are described as easy to clean, dustproof, wear-resistant, waterproof and odorless, indicating they require low-maintenance care.