It contains the same separation material as the Metrosep A Supp 5, is also made of PEEK, and is screwed directly onto the respective separation column with virtually no dead volume ("On Column Guard System"). The guard column prolongs the service life of the analytical column, with practically no influence on its chromatographic separating efficiency. The economical price and simple handling make using the A Supp 5 Guard/4.0 highly recommended.