[Saturn488]

I currently have a Celestron 2x barlow which I screw onto the camera nosepiece directly and works a treat.

I am looking at trying a 3x or even 5x. I have a Bintel 3x Barlow but for some reason it cannot be screwed onto the nosepiece as the threads are wider. Tried the 5x Svbony barlow as well but there is no lens section that can be unscrewed as it's part of the entire housing.

Does anyone know any other brand I can purchase to give this a go?