Cap Assembly, Double , 38mm, For Wash Reagent, 6'L, 1/8" OD tube for gas and liquid with 1/4-28 tube nuts and ferrules on the tube ends that connet to the delivery point. This assembly has 1/4 inch OD tube to transfer from bottle one to bottle 2. This assembly can be used to expand the capacity of a wash delivery system that originally has only one 4 liter bottle to having 2 each 4 liter bottles.