[ Aluminum Alloy] Made from high-quality aluminum alloy for wear and long-lasting durability.
[Precise Cnc Technology] Utilizes fine workmanship cnc technology for and durability.
[Compatibility] Female and male thread specifications of m42x0.75mm for easy interface with telescopes.
[Versatile Sizes] Various sizes ranging from 3mm to 30mm suitable for different telescope .
[Easy Installation] replacement for old or damaged parts, ensuring reliability in usage.

Spec:

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 length 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

How To Use:
1. Remove the objective lens.
2. Connect the telephoto tube to the eyepiece and the objective lens.
3. Then connect the objective lens.

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.