Opti Ms is our widest last with 100mm on the reference size 42 and has a circumference of 270mm. It is available at Jaure II Ms High / Mid, Professional II High Regular, Hiking II Ms High / Mid and Park. Then there is the Opti S which is used on the Jaure II Lt High and it is about 5mm narrower and 5mm smaller in circumference. But there is a larger last called Regular Ms and it is a little less wide with 97mm while the circumference is 275. Sometimes that last usually works better even for those who think they have wide feet. Professional II High Regular is available on this last, but also Forest II.