At the end of the 60s with the explosion for the demand that Seiko itself had helped promote Grand Seiko launched the mechanical. V.F.A. line. V.F.A stands for "Very Fine Adjusted" and as the name implies its distinguishing characteristic was its high precision. With it the Grand Seiko team achieved an accuracy that far exceeded that required by any chronometer certification. The GS standard at that time was set at +5 to -3 seconds per day but V.F.A. achieved an astonishing rate of +/-1 minute per month a level unprecedented for any mechanical wristwatch.