Tractors experts at TractorData.com explain Roll-Over Protective Structures (ROPS):
A roll-over protective structure (ROPS) is a frame designed to protect a tractor operator if the tractor rolls. ROPS acts by limiting most rolls to 90-degrees. In the case of a full roll-over, ROPS protects the operator from being crushed by the tractor. On tractors with loaders, the ROPS is often equipped with an overhead structure to prevent dropped object from hitting the operator, this is known as a falling-object protective structure (FOPS).
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