I just enlarged the hole in my kegerator to allow three 3/16 ID beer lines (that I use for CO2) to get in. With the secondary on the outside. But you could replace the secondary tank connection with a barb or mfl connection. It’s just a 1/4 npt: LTWFITTING Brass Fitting Coupler 5/16-Inch Hose Barb x 1/4-Inch Male NPT Fuel Gas Water(Pack of 5) https://www.amazon.com/dp/B077PMWRX4/ref=cm_sw_r_cp_api_glc_fabc_izG.Fb83CGV4N