M42-M48 Spacer - 16.5mm

Name: M42-M48 Spacer - 16.5mm
Brand: ZWO
SKU: ZWO-T2-M48-16.5
Price: 12.42 USD
Availability: InStock
Rating: 4.4 (5 reviews)

$12.42 ~~$18~~ In stock

Category: Astrophotography Accessories

Description

This adapter goes from M48 to M42 thread, and provides 16.5mm of spacing. This helps you achieve correct back distance for corrected optics.

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Customer Reviews (4.4 / 5 · 5 reviews)

Joseph G. ★★★★★ Oct 17, 2026

The threading is smooth and precise—no wobble or cross-threading when I attached it to my corrector. Finally got the exact spacing I needed for my field flattener. This little ring solved my focus issue instantly.

David M. ★★★★★ Oct 13, 2026

Needed exactly 16.5mm to hit the back focus on my corrected refractor and this hit it dead on. Threads are clean on both the M48 and M42 sides, no cross-threading at all. Stars are round corner to corner now.

Zoe N. ★★★★★ Sep 14, 2026

Threaded straight onto my field flattener without any cross-threading, and the 16.5mm spacing landed my back focus right where it needed to be. Stars are round to the corners now instead of the elongated blobs I was getting before.