This useful Universal Adapter from Baader Planetarium serves two purposes: 

1. Enables you to fit either T2 or 2" SCT threaded photo-visual accessories to Celestron Nexstar 4SE, C90 or Meade ETX telescopes. 

2. Serves as a low-profile (7mm optical length) 2” SCT-T2 adapter, enabling you to fit T2-threaded photo-visual accessories to most SCT telescopes. 

Comprises two parts: 

Part a: Converts the back of Celestron Nexstar 4SE, C90 or Meade ETX telescopes to standard 2” SCT so enabling you to fit photo-visual accessories intended for SCT telescopes (i.e. a diagonal or focuser).  Also accepts 1.25” astro photo/visual filters, i.e a light-pollution-reduction filter or UV/IR (using a filter usefully prevents dust and moisture from entering the rear of the telescope).  

Length: 10mm

Part b: Has as a female SCT thread on the telescope side and a male T2 thread on the other so is essentially a low profile SCT-T adapter.  Also, when used with Part-a, it converts the non-standard thread on Celestron Nexstar 4SE, C90 or Meade ETX telescopes to a T2 thread. The T2 threaded ring can be rotated for convenience.

Optical Length: 7mm

When part-a & b are used together the total physical length is 26.5mm

Please note: Manufacturers sometimes change the thread specifications used on their telescopes for their own convenience so we cannot guarantee compatibility, if found to be unsuitable you are welcome to return the Universal Adapter within 30-days of receipt for a full refund.