Good site to check on Specs.... I forget where I saw this but the last digit of the 525, the last "5" is the fifth version of the loader which is for L3901/L3301. Before them, LA524 was for the L3800/L3200, before that LA463 was for L3400/L2800 (which was measured at the tip of the bucket (?maybe?) but still lifts the same amount).