Baader M48 Extension Tube 40 mm

Baader M48 Extension Tube 40 mm

This Baader extension adds 40 mm of optical length to an M48 threaded imaging train. It provides an M48 × 0.75 female telescope-side connection and an M48 × 0.75 male camera-side connection.

Thread and clearance dimensions

The female thread is 3.5 mm deep and the male thread is 3 mm long. The manufacturer lists a 45 mm inner diameter and 53 mm outer diameter. The 40 mm extension is the added optical spacing, rather than the overall dimension including the male thread.

Spacing applications

The aluminium extension provides a fixed spacing increment between compatible cameras, reducers, flatteners and other threaded accessories. Combine it with the model-specific adapter arrangement required by the optical corrector.

Alternative 2-inch nosepiece use

This longer version also functions as a 2-inch Safety-Kerf nosepiece. When inserted into a suitable 2-inch clamp, the insertion depth is 36 mm and the remaining optical height is 4 mm. That 4 mm configuration is different from its 40 mm threaded-extension configuration.

Baader manufacturer documentation

Compatibility notes

Exact extension SKU and nominal optical length checked against the manufacturer variant. Exact optical length takes priority over broad catalogue filter buckets. Thread engagement length is not added again to the optical spacing. The 30/40 mm models have a second nosepiece function; their 4 mm push-fit optical height is not treated as the threaded extension length.

Additional specifications