The ZWO M54 to M48 Adapter has been independently developed by ZWO and is primarily used to connect a ZWO 2" Electronic Filter Wheel (EFW) or ZWO M54 Filter Drawer via an M48 thread.

This adapter provides a female M48 thread on the telescope side, allowing compatibility with a wide range of M48-based optical accessories.

The adapter has an optical thickness (backfocus contribution) of just 2 mm, making it ideal for precise imaging trains where back focus must be tightly controlled.

The outer edge is knurled to improve grip, making installation and removal easier, even when wearing gloves.

Example: Achieving a 55 mm Back Focus Distance

The following examples illustrate how this adapter can be used within an imaging train to achieve a total back focus distance of 55 mm, commonly required for many astrophotography setups.