The vertical level switch from Mobrey carries a stainless steel sheathed permanent magnet which rises and falls in the glandless pressure tube with changing liquid level. Switching achieved with the unique “3-magnet” system, giving snap-action “latch-on” switch. A switch mechanism is mounted the enclosure adjacent to the pressure tube. Vertical movement of the float magnet in the pressure tube simultaneously actuates the secondary and tertiary magnets in the switch mechanism to operate the contacts.