Can you add a filter to erecting EP?

[zainraza]

I've tried adding my moon filter to my 20mm but theres no way I can see to screw it on, I've tried take the lens apart in case you're meant to attach it inside but I'm getting nothing

[valleyman]

there should be a screw thread inside the EP Barrel and a screw thread on the moon filter.

A photo may help so we can see the problem

[John]

I'm not sure an erecting eyepiece is supposed to be used for nighttime observing to be honest so it's probably not fitted with the threads to take filters.

Could you provide a bit more info on your scope and the accessories you are using ?.

[zainraza]

I think you're right as I don't see a screw thread inside the barrel

I've got a Astromaster 130-EQ and using the EPs that were provided. I think the erecting eyepiece must only be really used for terrestrial viewing