The FoneMate is an adapter from Tele Vue meant to act as a linking point between one of their Dioptrix compatible eyepieces and a smartphone.
This smart phone adapter is compatible with phones falling roughly in to the following width x height ranges and measurements;
60 x 114 mm (2.3-inch x 4.5-inches) to 120 x 212 mm (4.75 x 8.3-inches).
It makes it a breeze to start imaging, allowing you to use your smart phone's inbuilt camera to take afocal astroimages that are sure to capture your imagination. This is a great tool for testing out if you would like to make the upgrade from visual to photographic astronomy, and remarkably easy to use.
Images show how the clamps extend for the largest phones, how a phone looks in the adapter and attached to an eyepiece, and its different sides.
(The phone, eyepiece, diagonal, and focuser shown are for demonstration of use purposes only and are not included.)