It's marked "AMO". Actual string length according to AMO stadards adopted in Feb of '68 state that the string length is 3" less than the bow length when measured under tension.
If the string maker is making and measuring their strings correctly, order a 59" string (or a 62" AMO string). There seem to be precious few who are doing so though.
Order a 12-strand 58" dacron string from the majority of makers and it'll settle in on the bow at 59". Order a 58" low-stretch string for a 62" AMO bow and you'll have a very high brace height! That's why strings are properly measured pre-stretched and under tension. I ran into this problem a number of years ago while trying different strings from a well-known maker... ordered and received strings that measured the same, but braced the bow at wildly different heights.
Standards were put in place for a reason and a big pet peeve of mine is bowyers and string makers who don't follow them or worse yet, don't follow them and still mark it "AMO"!!