Standard mixers are the oldest technology in two-part adhesive dispensing. These nozzles are round and come in a wide range of connection types. They typically require longer nozzles and more mixing elements to create the same mixing quality as Quadro mixers.  Quadro mixers are the newest technology for two-part dispensing and are square in shape. They allow for more complete mixing in a shorter nozzle so users can get closer to their substrates when dispensing. There is also less wasted adhesive left over in the nozzle.