"Wheelchairs, power chairs, and scooters gain smooth, easy doorway access with this adjustable indoor/outdoor aluminum threshold ramp by Prairie View Industries. Suitable for most weather conditions, the highly portable ramp has a grooved surface for enhanced traction and two adjustable casters underneath to fit any threshold from 2-3/8"" to 3-1/2"". Many sizes are available to fit most doorways, and the ramp can support up to 800 lbs."