Aligns The Phone Lens With The Binocular Lens For Photos And For Videos. Reinforced Cast Aluminum Frame Keeps A Tight Grip On The Binoculars, While Spring Loaded Phone Clamp, Also Of Aluminum, Holds The Smartphone Tight. Eyecup Width Between 24-46mm, Which Covers The Spectrum Of Optics. Phone Widths Between 62-104mm Will Fit (Iphone 5 Sans Case Is Too Narrow). Folds Down To A Small Size That Easily Fits In Pocket.