1) there is an image on the back that helps you figure out where to put the stamp, the address, and the note ; and
2) it is already cut to the 4"x6" size that is fairly standard worldwide for postcards; and
3) it is on the heavier weight Portfolio RC stock.
I don't make a point of buying it normally - I'm usually content to either use 5"x7" or cut down 8"x10" sheets of regular RC paper to three 4"x6" sheets plus a stub for exposure and toning tests.
Be careful about using 5"x7". I sometimes use that in Canada, because we don't have a preferential postcard mailing rate here, but in the USA, 5"x7" is too big to qualify for the really nice $0.28 postcard postage rate.