"The HangTime Hook allows adjustment for level, horizontal and vertical operation, and for viewing on a diagonal lay. It receives phones that are 3.5″ (90 mm) wide in various cases.
The HangTime Hook phone holder may receive guy lines for stabilization, may be locked in place along the ridgeline by securing an elastic hair tie with a larkshead knot to the ridgeline and attaching to the lower tie down. The tie downs also take up slack in headphone cables and manage USB cords from power banks. Sewing a button to a velcro strap allows hanging flashlights, power banks, and even drinks to the side of the HangTime Hook in the keyhole slot."
The above wording is straight from Ridgeline Media Systems.
A great device to watch movies on your phone, hands-free calls and change media/music while you relax.
A video showing you just how easy it is to install on your ridgeline.