Micro Switch used to control drive motor and "ride" the CAM.
2500, 2510, 2750, 2850, 2900, and 9000 / 9100 / 9500. ( also used ( 2 of them ) inside front cover of Fleck electronic valves like 5600SE, 5600 SXT ).
NOTE: This Switch ( 10218 ) when used on Fleck 9000,9100,9500 power head is closer to the Timer Assembly ( left side ) and the one next to it ( 16433 ) will sometimes BREAK on the Fleck 9000, 9100, 9500 power head, and this is a result of the DRIVE MOTOR ( 18738 ) running backwards.
The Drive Motor should be REPLACED to solve this issue.
Reference = Switches Breaking Fleck 9000, 9100, or 9500 ValvesAlso - NOTE: Starting in 2019, Fleck ( Pentiar Water Treatment ) starting using ( 2 ) 16433 switches, and no longer used the switch 10218 on their Power Heads ( 9000 / 9100 / 9500 ).
NOTE: Besides physically breaking, this switch can be the problem if the timer completes a full cycle in about 2 minutes and starts again ( never stopping at any of the regeneration cycle positions ).
Two are used on the Fleck 5600SE or 5600SXT Valves behind circuit board and "riding" the Cycle Cam.