Bagpipe Drone Top Stoppers are an essential part of your pipe box maintenance kit. They are used to shut either one or all of your drones off. The tension on the quick stop drone valve is screw adjustable giving greater accuracy and once properly installed to suit your blowing strength the Quick Stop Drone Valves should ensure that you strike your bagpipes in without difficulty, provide a steady flow of air to your drone reeds and close tightly when pressure is released to ensure a clean 'cut-off'.