Column Protection System Guard Column Holder for EC 4 x 2 mm and 4 x 3 mm guard columns - consisting of:1 x Guard column holder, 2 x Capillaries (ID 0.12 mm), 3 x Ferrules (for HPLC columns with particle size > 2 µm), 3 x Ferrules (for HPLC columns with particle size < 2 µm), 2 x Wrenches (wrench size: 12 and 14 mm), 1 x User manual