BikeMaster Folding Bar End Mirrors BikeMaster Folding Bar End Mirror has a beautiful case mirror backing plate and arm are one-piece, eliminating screws and mirrors vibrating loose. They have a patented feature that allows them to quickly be folded in, reducing the width of the bike, and making them less conspicuous. Features: Ball joint that allows them to quickly be folded Nylon swivel allows just the right amount of tension to be maintained for easy adjustment Bar end adapters included Sold in pairs Specs: Fits 7/8 handlebars only Dimensions: 3 5/16Diameter x 9/16 Depth Stem Length: 2 1/2 Note: Mounts externally and internally on 7/8 bars only.