Take advantage of your phone's planetarium and sky maps by placing it on your telescope.  A handy accessory to have your sky map right in front of you.  (most phone apps have observing mode which turns your phone screen to red not to bother your eyes when obsering) 
 
The phone holder comes with vixen style dovetail and is padded to secure and protect your phone.  The holder can securely hold phone from 2.25" to up to 3.75" wide.  
 
The vixen style dovetail can either be inserted into a vixen type saddel or directly to your telescope with two holes 1.25" apart.