Any loose fill surfacing, like rubber mulch or engineered wood fiber, is going to need a retaining wall, like ParKurb Borders. The borders will create a solid wall to keep the play surfacing in place. However, if a full or half-length wheelchair ramp needs to be added, these Border or Ramp End Caps come in handy. The timbers are designed to overlap with a stake that goes through the center that anchors it to the ground in an upright position as well as connecting the two pieces. Placing a ramp requires taking out one of the timbers and leaves a dangerous staking sticking out of the ground from 4- to 6-inches. With the Border or Ramp End Caps, that stake becomes safely encased in a plastic cover preventing injuries and creating a finished look to your safety surfacing retaining wall.