The SV213 series Balor mirror is our brand's first three piece apochromatic Balor mirror product. The product positioning is mainly visually compatible with photography; The main purpose of supplementing this series of Balo mirrors is to solve the color difference problem of twopiece Balo mirrors of the current brand and complete the product level of Balo mirrors. 1. The SV213 1.25 "3xBarlow lens is designed with air separation, full multilayer coating, and 3element color correction.   3. The Barlow lens has a compression ring that leaves no marks on the camera or eyepiece.   5. Suitable for any 1.25 "focusing device or diagonal, recommended for planetary and lunar imaging and visual observation. Specifications: 1. Brand: SVBONY 2. Model: SV213 3. Gun barrel size: 1.25 inches 4. Magnification factor: 3X 5. Number of lenses: 3 pieces 6. Lens coating: Full multilayer coating 7. Upper body length: 2.30 inches/58.5 millimeters 8. Insertion depth: 1.02inch/26mm 10. Net weight: 3.14oz/93g 11. Filter thread: M28.5x0.6 12. Tube material: Aluminum alloy 13. Hand twisted screws quantity: 2PCS 14. Hand twisted thread specification: M4x8 15. Compression band/ring in eyepiece holder: Yes The package includes: SV213 3x 1.25 "Barlow lens with 3 elements 1PCS bolt box 2PCS M4 screws 1PCS dust plug 1PCS cap