1. [DURABLE ALUMINUM ALLOY] - High-quality material for wear resistance and reliability in use.
2. [PRECISE CNC CRAFTSMANSHIP] - Crafted with CNC technology for superior accuracy and longevity.
3. [8 SIZES INCLUDED] - Range of sizes from 3mm to 30mm for versatile compatibility with different .
4. [EASY CONNECTION] - Female and male thread specifications (M42x0.75mm) for seamless installation.
5. [WIDE COMPATIBILITY] - Suitable for extending the length of astronomical telescopes and microscope lenses.

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

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.

PackageList:
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

Notice:
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.