ISO 12003-1 specifies procedures for both the static and dynamic testing of roll-over protective structures (ROPS) front-mounted on narrow-track wheeled agricultural and forestry tractors. It defines the clearance zone and acceptance conditions for rigid or tiltable front, two-post ROPS, includes any associated rear fixtures, and is applicable to such tractors, so equipped, having the following characteristics: a ground clearance of not more than 600 mm beneath the lowest points of the front- and rear-axle housings (not considering lower points on the axle differential); a fixed or adjustable minimum track width of one of the two axles of less than 1 150 mm when fitted with the widest specified tyres, and with the overall width of the other axle being less than that of the first axle; a mass greater than 600 kg but less than 3 000 kg unladen, including the ROPS and tyres of the largest size recommended by the manufacturer.