Extension ring / extension ring SP54 – M54i to M54a, length 11mm.
The extension ring is required to connect the Hyperion DT
Rings SP54/M28 and SP54/M37 to Hyperion Zoom Adapter M43/SP54.
Thread SP54 on both sides (internal or external thread).
The Hyperion Mark III zoom eyepiece can be fitted with an adapter and a
DT ring can be connected to the filter thread of a photo lens.
This allows you to take pictures through the eyepiece. The DT rings
SP54/M28 and SP54/M37 absolutely need this extension.