The surface is a tarp that is inflated soft enough to be difficult to jump or walk on without falling.<br>The Pair
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/47523448@N00">texas_mustang</a>
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/47523448@N00/10766757">Flickr</a>