Hypersil HPLC Column Prep BDS SI 25x250mm. Hypersil HPLC Column, Preparative BDS SI, XtendedLife, Normal Phase, Particle Size: 5um, Pore Size: 145A, Max. Pressure: 3500psi (240 bar, Ph: 2-7, Surface Area: 185m2/g, Carbon Load: 11%, Dimension: 25x250mm, improves lifetime by maintain a packed bed