PrimaLuceLab M110 35mm Extension Tube for Esatto 4" 

The M110 35mm extension tube can be directly threaded to the ESATTO 4" draw tube and allows you to fix camera and accessories further away from the ESATTO microfocuser. This M110 extension tube has 35mm thickness, it's made up of aluminum, black anodized and it has a M110 female on the camera side this way you can connect all the ESATTO 4" camera adapters.

TWO of these are required to mount Esatto 4" + ARCO 3" + TOA-645 flattener kit on the TOA-130.