Capillary Column Caps Back to: Capillary Column Caps Capillary Column Caps Product Code: 22858 Silicone Column Caps, Pack of 10 Price £31.00 Description Attach to the column in seconds to form an airtight seal. Increase column lifetime—prevent moisture and air from entering the column during storage. Two styles to choose from: glass or silicone material. Glass caps are color-coded for identifying detector and injector ends. Not recommended for reuse.