New Mizuno MP-18 muscle back Images released at The Open Championship Posted in: Uncategorised Share TwitterFacebook As has become tradition, Mizuno took the start of the Open Championship as an opportunity to circulate the first few pictures of its new MP irons. The new MP-18 is due for release this September. Legendary club maker Turbo inspects the MP-18 on the Yoro line. The new Mizuno MP-18 muscle back. MP-18 in the hands of our Yoro master craftsman.