The pool water level and vacuum monitor is a device that is adapted to be seated on a pool deck adjacent to a swimming pool, and which monitors water level when filling a pool liner whilst a vacuum is removing air from behind a pool liner and a concrete wall of a pool. Moreover, the pool water level and vacuum monitor includes a telescoping armature that extends aside of a housing. The telescoping armature includes a cord and a float member on a distal end of the cord. The float member is adapted to rest on a pool surface of the swimming pool, and moves to close a float switch integrated in the float member. The float switch is able to turn off all circuitry associated within the housing.

A switch unit includes a substrate, which includes a hard layer and a soft layer; a first contact point above the soft layer; a second contact point around the first contact point; a conduction spring member which is elastically deformable into contact with the first contact point to make a conduction between the first contact point and the second contact point; a first external electrode; a first through-hole electrode which is electrically connected to the first contact point; and a first wiring pattern, which is electrically connected to the first external electrode and the first through-hole electrode.

A heat destructive disconnecting switch, comprising a first conductive member, a second conductive member, a movable conductive member, an overheating destructive member, an operating component, and a second elastic member. The movable conductive member enables electrical conduction with the first conductive member and the second conductive member. A first elastic member having a first spring and a second spring which are compressed and provided with a first elastic force, and the second elastic member is provided with a second elastic force. When the overheating destructive member is destructed due to overheating, the first elastic force is diminished or vanished, which causes the second elastic force to be larger than the first elastic force and forces the movable conductive member to disconnect from current conducting state between the first conductive member and the second conductive member, thereby achieving a protective effect from overheating.