It allows your tractor production rate to increase, so you can harvest more products. The tractor provides the multiplier value to the products you will harvest. You can have only 1 tractor and use it for all your products. FTY tokens spent for the tractor cannot be recovered. tractors stay with you forever. You can use FTY token for tractor purchases. When you buy a tractor, 100% of the FTY tokens spent will be burned.