8407.90.90.40 - 746 W or greater but less than 4,476 W

This HTS category, 8407.90.90.40, covers spark-ignition internal combustion piston engines that are not specifically designed for aircraft or vehicles, and fall within a defined power range. Specifically, these are engines with a power output of 746 Watts or greater, but less than 4,476 Watts. This classification is applicable to a variety of stationary or portable engines used in applications such as generators, pumps, lawnmowers, and other industrial or domestic equipment where this specific power output is required.

Distinguishing this category from its siblings, 8407.90.90.20 covers similar engines with a power output *less than* 746 Watts. Conversely, 8407.90.90.60 and 8407.90.90.80 classify engines with significantly higher power outputs, starting from 4,476 Watts and exceeding 18.65 kW, respectively. Therefore, the defining criterion for this specific sub-classification is its intermediate power range between 746 W and 4,476 W.

As this node represents a leaf node within the HTS structure, there are no further subcategories to introduce. Classification at this level is determined by the engine's spark-ignition type, its reciprocating or rotary piston design, its exclusion from aircraft or vehicle-specific provisions, and its precise power output falling within the specified range.