4FT Wheelchair Ramps are available for 4 inch -12 inch step heights only. Note: Please refer to the buyer s guide to select the wheel chair ramp for home steps size before purchasing; Please notice that it is normal for the long portable wheelchair ramp to sink during use, and it will rebound soon.Please do not exceed the maximum weight capacity of this wheelchair ramp 600 lbs. Double Non-skid: the aluminum surface of the wheelchair ramps for home is designed with folds to increase friction. The surface is also covered with non-skid layer for double non-skid protection. The handicap ramp can be fixed on the wooden platform with complimentary screws. Portable & Comfortable: the 4 foot wheelchair ramp is made of advanced aluminum material, which is firm and light, and can be folded for easy carrying and storage.