Open Core Connection or Rock Interlock as we sometimes call it, relies solely on the interaction of rock in GeoStone's large open core for connection.  Other wall systems come with a separate element that may have to be purchased in order to "complete the connection" or "align" the product.  These items can come in the form of a pin, rod, or claw of some sort and can become a very costly portion of retaining wall construction.

Still, there are other wall systems that use built-in forms of connection or alignment such as lips and lugs.  These forms mandate a specific setback or batter in the wall and cannot be changed without modifying the block itself with a saw or grinder.  This will slow down wall construction considerably.  Such hindrances will be most evident in stairs, battered radii, and required vertical applications.

The GeoStone retaining wall system is not limited in such ways giving the installer complete freedom of installation.  It also provides the most powerful connection on the market.  The angular crushed limestone (#57 or #67) in the cores provides an incredible amount of friction, much more than a pin or lip.  The large open core filled with crushed stone (aka - free draining material) also allows for maximum drainage.  Any professional installer will agree that when it comes to modular retaining walls, compaction along with superior connection strength and maximum drainage properties are key in building a successful wall.