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M42 1.25" Spacer Ring Set — 3/5/7/15/20/30mm — M42x0.75 Threaded Extensions (Male/Female) — Fine-Tune T2 Backfocus for Astro Cameras, OAGs & Filter Trains — 6 Rings

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Product details

Management number 218516835 Release Date 2026/05/03 List Price $16.64 Model Number 218516835
Category

Key Product Features 1. **Exact Spacing in Seconds:** 6 rings (3/5/7/15/20/30mm) stack to create 3–80mm of spacing for dialing in your imaging train. 2. **True T2 / M42x0.75 Threads:** Male + female M42x0.75 on every ring for clean, secure stacking with common T2 accessories. (Not M48.) 3. **Built for 1.25" Systems:** Compact spacers that fit perfectly in 1.25-inch setups—great for small astro cameras, guide cams, and tight builds. 4. **CNC Aluminum, Matte Anodized:** Lightweight but rigid all-metal rings with a low-glare finish; threads start smoothly and tighten confidently. 5. **Stable, Repeatable Fit:** Precision machining helps keep your train aligned when you add/remove spacing—ideal when tuning reducers/flatteners. What’s in the Box **Six M42 Extension Rings:** 3 mm, 5 mm, 7 mm, 15 mm, 20 mm, 30 mm **Thread Specification:** M42×0.75 male on one side + M42×0.75 female on the other (stackable) **Compatibility:** For T2/M42 threaded accessories commonly used in 1.25" astrophotography trains

  • **Flexible Spacing, One Kit:** Mix and match six rings (3/5/7/15/20/30 mm) to build the exact distance you need—adjust from 3 mm up to 80 mm total for imaging trains and projection setups.
  • **M42x0.75 on Both Sides:** Every ring is threaded male-to-female for quick stacking and secure connections with T2/M42 components (T-rings, OAGs, filter wheels/holders, adapters). *Note: This is M42/T2, not M48.*
  • **Sized for 1.25" Setups:** Designed to integrate cleanly into compact 1.25" systems where space is tight—ideal for small astro cameras, guide cameras, and lightweight optical trains.
  • **CNC Aluminum, Matte Anodized:** Rigid all-metal construction with a non-glare anodized finish; cleanly machined threads help parts start easily and tighten smoothly.
  • **Consistent Fit for Repeatable Results:** Accurate machining helps keep your camera train stable when you change spacing—useful when dialing in reducer/flattener distances and maintaining reliable focus positions.
Brand starboosa
Mount Altazimuth Mount
Focus Type Auto Focus
Model Name M42
Unit Count 6.0 Count
Finderscope Straight-Through
Manufacturer Starboosa
BuiltIn Media 1x M42 1.25" Spacer Ring Set
Compatible Devices Camera, Filter, Adapter
Additional Features Exact Spacing for Astrophotography, T2/M42 Compatibility, Compact Size for 1.25-inch Setups
Warranty Description 1 year warranty
Objective Lens Diameter 44 Millimeters
Manufacturer Part Number SB1140TF
Item Dimensions D x W x H 1.73"D x 1.73"W x 3.3"H

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