Features: Under fully multi coated lens can offer a real color reproduction and no color distortion;let you enjoy a clear and bright images. Aluminium drawtube with safety undercut on the lower barrrel and a metal rings that is both attractive and practical. 1.25" Diameter(31.7mm) eyepiece for astronomical telescopes. Focal length: 4mm/10mm/23mm optional, you can freely observe objects with different distances and sizes. Lens material uses high-grade optical glass to achieve a clear views and excellent contrast. Specifications: Material:Alloy Focal length: 4mm,10mm,23mm Interfaces size: 1.25 "(31.7mm) Field of View: 62° Package Includes: 1x Telescope Eyepiece note: Please allow 1mm errors due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item.