Selected Blazer Sizing

hello,

I'm struggling to identify a nice blue blazer between £50 and £100. Selected Double buttoned blazer Dark Blue - House of Fraser I really like that but am unsure about the sizes. Are those sizes continental? i'm a 40 chest which in continental terms is a 50. I cannot figure it out. I looked at the brand 'selected' went on their website and all their sizes started at a 46 which made me think that they do work in continental sizes. Thoughts.