Bel-Art Polyethylene 8 in. Drying Tubes with Polypropylene Tube Fittings (Pack of 12) (F19962-0000) Unbreakable polyethylene straight tubes, 16mm ID by 19mm OD Each tube is supplied with two polypropylene fittings which accept 6.4 to 9.5mm (1/4" to 3/8") ID tubing Drying agent not included Can be filled with desiccant of your choice