A telecommunications system using a hose model having a VPN network. The ball valves include a valve body, a ball, a valve seat, and an annular spring. The scroll cam includes a cylindrical cam, a plurality of cam grooves formed on the cylindrical cam, a drive system for rotating the scroll cam, and a moving element. The stem portion of the replacement structure is permanently attached to sidewalls of the via so as to electrically couple the head portion of the replacement structure to the via. And this invention also relates to a drug for treating arrhytmia having the prolongation effect on the functional refractory period comprising said compound or a pharmaceutically acceptable salt thereof as an active ingredient.