1. Focal length: 7-21mm
2. Zoom type: linear
3. Lens structure: 6pcs / 4 groups
4. Eye protection: 18mm-16.3mm
5. Pupil spacing: 15mm
6. Field of view: 57-40 degrees
7. Coating: fully multi-coated green
8. Tube size: 1.25 inch
9. Thread size: M28.5 x 0.6
10. Overall length: about 93mm
11. Net Weight: about 133g

Features:
1. Fully multi-coated premium eyepieces that can zoom any focal length between 7-21mm
2. Can instantly amplify low power to high power
3. Compatible with any telescope that accepts a 1.25-inch eyepiece
4. 6-element, 4-group premium optical design
5. Comfortable 18mm-16.3mm relief, perfect for eyeglass wearers