Applicable size and alignment Designed for optics with an eyepiece outer diameter of 24 mm to 47 mm and smartphones with a width of 55 mm to 100 mm. A 10 mm light hole aligns easily with your phone camera and helps shield stray light to improve image contrast. Please confirm that your device dimensions fall within these ranges. Easy and protective design Large diameter locking knob makes locking the eyepiece straightforward and comfortable. Soft padding protects your phone from three directions, and the screw locks hold the phone firmly and stably. Broad compatibility Suitable for binoculars, monoculars, spotting scopes, and telescopes. Works with almost all smartphone brands, with or without a case, from small to large. Rapid image alignment The camera and optics can autoalign at the center. Quick Alignment Version makes setup fast and easy, enabling you to align the camera and optics in just a few seconds. Practical use scenarios Bird watching or wildlife photography: attach your smartphone to a binoculars or spotting scope to capture distant subjects without missing moments. Astronomy and stargazing: pair with a telescope to photograph the moon, planets, or night skies with ease. Field observation and education: use with a monocular or scope for quick, hands documentation during field trips or learning activities.