... . Interlox Saddle Ringf. Teller Rosetter Ringg. Heilex Ring2. Plastic Balls (Materials: PP, PVC, CPVC, etc.)a. Polyhedral Hollow Ballb ... ,PP, RPP, PVC, CPVC and PVDF.2) Main types: pall rings, polyhedral hollow balls, conjugate rings, teller rosetterings, cascade rings, ... saddles, VSP, helix rings, hollow balls.3) Advantages:a) Big free volumeb) Low pressure dropc) ...