Innovative StaLok Waterless technology transforms natural 2MM crushed stone into a unique natural bunker liner. Patented polymer technology gives the bunker liner increased strength, resulting in increased traffic resistance, but also maintains a degree of flexibility. This prevents the material from becoming too rigid like concrete and other chemical liners. Its unique surface characteristics resist weathering from water. StaLok simply needs compaction to activate, saving you time and water during installation, without fabric or staples to get in the way.