It was invented by German BASF, the first generation  Random packing. To compared with Raschig ring, the most important improvement is increase two row of  inward ligule. It promotes liquid-gas liquidity and improve tower’ s packing’ s mass transfer performance.  

Flat ring is also called SMR(Super Mini Ring), It s an advanced random packing in the column tower packing. It has similar structure with cascade mini ring, There is not flanging structure at the top and bottom. It can improve the packing strength through adjust the arc of internal blade. It has reasonable flow structure, low pressure drop and high mass transfer performance. Super mini ring has two main types, which names as QH-1 and QH-2.  

It was developed by British company MTL Ltd, which also called CMR. Ceramic Cascade Ring is a new type of bulk packaging with the advantages of high capacity,good stain resistance and low pressure drop.Its sides have one or two beveled edges, which have hhigher mechanical strength and better gas passage than pall rings.Ceramic cascade rings feature a rectangular opening,curved leaves,tapered edges, and reduced height

Owing to this pack’ s shape is like saddle, so called saddle ring or Berl Ring. The earliest saddle ring’ s material is ceramic. In our actual application, when gas flows upward, liquid will flow downward along with arc channel. This Movement way will directly reduce wall flow’ s happening. However, Arched external frame also cause overlapping & bridging . Therefore, scientists change two ends into rectangle type contact surface. This improvement will reduce bridging’ happen.  

It was one improved ring based on Intalox ring's struxture. The biggest improvement is that Intalox saddle's arc profile will be change wavy or jagged profile.Meanwhile, increase some pores in the arc liquid channel's middle position. This structure's change not only increase packing's contacting gap,but also improve gas and liquid's movement and distribution in the packing layer.

It is a earliest development of random packing, which its height is equal to outside diameter.Raschig ring was invented by German Chemist Friedrich Raschig in 1914, it also marks that the development of fills hds entered a scientific track .However, in the actual application, such as "wall flow, channel flow and so on" often happened in packed bed.