These M4 hop arms have been developed to fit Pro Win, SHS and our own hop unit and come with a concave nub.
The flat hop arm’s has been designed and developed to apply the nub flat to the barrels bore to give maximum hop efficiency.
These have been made to be easily installed into your hop unit by following out simple instructions here on the website.
Purple = Flat hop
You will need a flat hop ready bucking and a barrel with a suitable window.