mpo55Mizuno MP-55 Yoro Craft Irons – In Japan Mizuno offers the MP-55 instead of the MP-25 why? I don’t know but I do know after hitting the MP-55’s that they are indeed specialMelting Point System MP55 Simple and Versatile. The MP55 is the ideal starter model and offers simultaneous determination of up to 3 melting pointmelting range or 2 slip melting point