Features:
* Anodized aluminum with matte internal thread effectively reduces glare; Focal length extension tube features M54×0.75 internal and external threads for a secure and durable connection.
* Meets Insufficient Rear Focus Distance: This focal length extension tube extends the distance between lens and camera, making it suitable for telescopes, lenses, MPCC, guide glasses and other devices, which ensures optimal focus.
* M54×0.75 internal and external threads enable secure stacking of washers and adapters; focal length extension tube maintains optical axis alignment for clear astronomical imaging.
* Available in various sizes: 3mm/5mm/7mm/10mm/12mm/15mm/20mm/30mm/40mm/50mm, meeting different rear focus requirements.
* Ideal for astronomical photography setups: Use the focal length extension tube with a focuser, field flattener, or filter wheel to finely adjust spacing for incisive, low-vignetting images.

Features:
* Product Name: Focal Length Extension Tube for Astronomical Photography Telescope
*Material: Aluminum
*Size: approx.
Internal thread: M54 x 0.75 mm.
External thread: M54 x 0.75 mm.
Length: 3mm/5mm/7mm/10mm/12mm/15mm/20mm/30mm/40mm/50mm
*Color: Black
* Weight: about 5-200g

Package includes:
1 x Focal Length Extension Tube