Thorough design: This phone clamp is made of high strength PA plastic and features adjustable locking mechanism with a steel bolt rather than a spring,which keeps your equipment from scratches or damage in the field and harsh weather conditions. Easy to adjust: Works great for the phone or binoculars in the up and down position taking pictures and recording sideways or in distance,which bringing you special and unique experience of exploring the nature of the world easily through your screen. Simple to use: Place your phone in the adapter, center your camera over the eyepiece,and use the knobs to secure the adapter in place. Wide Range of Applications:This universal adapter mount works with cell phone,microscope, telescope, binoculars, monocular, spotting scope. The eyepiece outer diameter range: 22-44 mm/0.86-1.73 inch,its compatible with most telescope eyepieces and any eyepiece with an outside diameter measuring from 29millimeter to 45millimeter. If You Are Not Satisfied with Your Purchase for Any Reason,Please Feel Free To Contact Us at the Buyer Center or Support Email For 24-hour online customer service.