Struggling with limited adjustment range on your telescope? Our 8-piece extension tube set solves this with accurately-machined aluminum adapters that maintain optical integrity. Whether you're capturing Jupiter's bands or the Orion Nebula, these M42-threaded tubes extend your primary mirror's optical distance without illumination leakage. The anodized black finish and internal baffling reduce reflections, while the aircraft-grade construction withstands repeated field use. Includes all essential sizes (3-30mm) in one ready-to-observe kit.

Item Type: Lens Extension Tubes
Material: Aluminum Alloy
Color: Black
Product Size: Approx.3mm / 0.12in, 5mm / 0.20in, 7mm / 0.28in, 10mm / 0.39in, 15mm / 0.59in, 20mm / 0.79in, 30mm / 1.18in, 12mm / 0.47in
Application: Extend the optical distance of the primary mirror of the astronomical telescope
Extinction Treatment: Internal with extinction thread
Interface Female Thread Specification: M42x0.75mm
Interface Male Thread Specification: M42x0.75mm

Package List：
1 x 3mm Extension Tube
1 x 5mm Extension Tube
1 x 7mm Extension Tube
1 x 10mm Extension Tube
1 x 12mm Extension Tube
1 x 15mm Extension Tube
1 x 20mm Extension Tube
1 x 30mm Extension Tube

Note:
1. Please allow 1‑2in error due to manual measurement. Thanks for your understanding.
2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.