PrincetonSPHER-100 C4, our most popular C4, is bonded on ultra high purity spherical silica. With a pore size of 100Å and an average surface area of 325 m2/g, these columns are perfect for method development or as equivalent columns in existing methods. Excellent batch to batch reproducibility and 25 years of bonding experience make this phase a great choice if you are looking for consistency and quality.