Abstract: Two components, such as a support tube and handset of a herbicide delivery lance, are interconnected in a manner which provides an electrical connection between leads in the tube and the handset respectively. Fluid communication is also provided between a flexible tube in the tube and a passage of the handset. The leads on the tube are connected to two terminal plates situated on the outer surface of the tube. These terminal plates move into positions opposite bosses on a sleeve provided on the handset when the tube is pushed into the sleeve. Screws, engaging bushes accommodated in the bosses, are then screwed into contact with the terminal plates to secure the tube in position. The screws also complete the electrical circuit between the leads. One of the components includes a valve which includes an operating member. Displacement of the operating member against the action of a spring not only opens the valve, but also actuates an electrical switch.