8PCS Black Telescope Extension Tube M54x0.75 Stackable Threaded Dazzle Proof Astronomical Telescope Spacer Kit

Feature: 1. Precision Back Focus Adjustment: This aluminum threaded adapter set includes eight M54x0.75 extension tubes in lengths of 3mm, 5mm, 7mm, 10mm, 12mm, 15mm, 20mm, and 30mm, allowing precise modification of the optical system back focus for accurate focusing with various imaging devices. 2. Stackable Threaded Design: Each extension tube features M54x0.75 standard threads, enabling secure stacking with adapter rings, spacers, and other optical components while maintaining coaxial alignment, offering flexible spacing adjustments for improved image clarity. 3. Enhanced Imaging Performance: By increasing the distance between the sensor and optical elements, these extension tubes resolve insufficient back focus issues, allowing eyepieces or imaging systems to achieve proper focus while reducing vignetting and image distortion at the edges. 4. Dazzle Proof Internal Structure: The black anodized outside with a matte interior effectively minimizes stray light and internal reflections, enhancing image contrast and purity during long exposure astrophotography or deep sky imaging sessions. 5. Astrophotography Compatibility: Designed for telescope systems, focusers, field flatteners, and filter wheels, these extension rings require a M54x0.75 interface for reliable connection and system stability, ensuring seamless integration with existing astronomy equipment. Specification: Item Type: Astronomical Telescope Extension Tube Color: Black Material: Alloy External Thread: M54x0.75mm . Package List: 8 x Astronomical Telescope Extension Tube