The s-max is a stair climbing aid and can be mounted to almost all commercial wheelchairs. You may remain in your own wheelchair, while you are safely and comfortably transported up and down stairs or across obstacles. can be mounted to almost all commercial wheelchairs compact dimensions and low net weight can be stored easily in your car single step mode easy operation and handling maximum lifting capacity of 155 kg or 180 kg suitable for a person's maximum weight of 115 kg or 135 kg