Celestron C90 / 4SE t-adapter #93635-A

The #93635-A allows fitting of a t-ring for prime focus (no eyepiece used) imaging through a Celestron 4SE and C90 (not the current model). The solid metal adapter screws on to the OTA in place of the visual back. With the current C90 model, you do not need this, and can connect a t-ring direct.