Please check the dimensions on the picture before ordering.

This fitting was common on old Bosch machines a long time ago, and some machines use it now, including all the Bigboi machines we have tested.   Note Bigboi has sometimes 2 connections, you want to connect it to the first connection closest to the trigger piece so the weight of the foam cannon is close to the trigger, this is the adapter that should fit.  but please check as Bigboi do not release information like this, and while we have spent a lot of time checking we don't know if there are some models that are different.  Please check by looking at the fitting and checking its dimensions match your machine before ordering.