Concrete PolyLock, also called E-lock or polylock, made of HDPE, E-shaped, is suitable for anchoring in concrete firmly. It is casted or embedded in wet concrete when using, for the exposed welding surface, geomembrane can be welded on it easily. The smooth surface with width 15cm or 10cm is for welding the polyethylene sheets while the 3-4cm height fingers are used to insert the web concrete to get locked-in and fix the joint with geomembrane to make a complete water-proof banking.