The Foba CEBLO 3/8 Interchangeable Adapter is a part of the Foba Combitube system.A 3/8" thread is featured in this conversion adapter to mount spotlightsIt is compatible to be inserted into the CEHUA, CEHUO, CEONA, or CEONO adapter sleevesThis conversion adapter can be bored in order to tighten it with a bar or screwdriver  It has a diameter of 18mm