1. Easy to install, perfect replacement for the old or damaged one, reliable to use.
2. Made from high quality aluminum alloy, which is wear?resistant and not easy to damage.
3. Using fine workmanship CNC technology, the accuracy is higher, .
4. The female thread specification of the interface is M42x0.75mm, the male threadspecification is M42x0.75mm.
5. Various sizes of 3mm/5mm/7mm/10mm/12mm/15mm/20mm/30mm are suitable for different .

Specification:
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 focal 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

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.