Aluminium material, more stable and durable. Suitable for 3.5"-6.5" cell phones. Anti-slip mats, protect your phone, avoid shaking and skidding. Widely compatible with many cell phones. Make navigation easier while riding on a bicycle or motorcycle. Not block screen, camera and earphone jack, not affect phone's normal use. Used for handlebar of bicycle and motorcycle, widely used for 20mm-38mm diameter handle of pram, supermarket trolley and car steering wheel, etc.