As you go up the chain, you have the same design but better and better pumps, which are both quieter and do a better job of cleaning. They also have extra sound absorbing material and suspension material to suppress the pump noise. There are now three models of the PRC-4. The PRC-4 Basic , the standard PRC-4, and the PRC-4 Deluxe.
All the PRC4's have 70% greater suction power compared to PRC3. The search for a pump of this specification at this price took many years . Do not confuse these pumps with the ones used in vacuum cleaner based machines. These are laboratory standard scientific pumps which are quiet and efficient. Set at 28 litres per minute flow for the pump ensuring even very dirty or warped records will be cleaned efficiently.