SV135 eyepiece is a good assistant for you to observe and take pictures of the planets. More comfortable to view the moon, Jupiter and Saturn. 36°-52° field of view. This is a zoom eyepiece considering that it zooms from 7mm to 21mm. which allows you to see different wide field of view under the same viewing conditions. Meet your different needs. Provide comfortable observation experience. 13-14mm wide eye relief can also provide an easy and pleasant viewing experience. It is also friendly to people wearing glasses. If you have a pocket monocular or binoculars,and you want to pictures or videos,then you can connect it to a tripod. Steps to install the phone: 1.Pull the phone support plate to the maximum (3.93in wide) 2.Put the phone in to fix it. 3.Turn the screw under the phone support plate to adjust the phone so that the camera of the phone is aligned with the eyepiece.