Electrical Scooter, WT-T4SU

The Electrical Scooter WT-T4SU is a motorized mobility device intended for medical purposes to provide mobility to persons restricted to a sitting position. It is powered by a lithium-ion battery, features four solid wheels, electromagnetic braking, and a maximum speed of 4 mph with a cruising range of 6.61 miles.

Compared to the predicate device (WT-T4QP2), the WT-T4SU is a larger scooter with increased dimensions (42.9" length vs. 36.2"), a larger seat (16.7" width vs. 13.4"), a more powerful motor (270W vs. 180W), larger front wheels (7.28" vs. 6.5"), and higher weight capacity (264 lbs vs. 250 lbs). Both share the same battery type, controller, brake system, and maximum speed, but the subject device lacks manual folding capability.

ISO 10993-5 and 10993-10 (biocompatibility); ANSI RESNA WC-2:2019 Sections 14 and 21 (wheelchair electrical systems and EMC); ANSI AAMI ES 60601-1 and IEC 60601-1-2:2014/AMD1:2020 (medical electrical equipment safety); IEC 62133-2:2017+AMD1:2021 (lithium battery safety); ISO 7176 series Parts 1-10, 13, 15 (wheelchair stability, dynamics, brakes, dimensions, obstacle climbing, friction); ISO 16840-10:2021 (fire resistance of seating).

The subject device is substantially equivalent because all dimensional and performance differences reflect its design as a larger-capacity variant of the predicate. The increased motor power (270W vs. 180W) is necessary to accommodate the larger scooter size and higher weight capacity (264 lbs vs. 250 lbs), raising no new safety concerns. The larger front wheels and increased ground clearance are minor variations that do not affect safety. The shorter cruising range (6.6 vs. 9.1 miles) results predictably from using the same battery in a heavier scooter, per energy conservation principles. Both devices use identical batteries, controllers, brake systems, and comply with the same consensus standards for electrical wheelchairs and scooters.