The Start and Stop buttons on the ALX-PRO chemical dispensing controller were originally a push-style and were experiencing some issues out in the field. We've since replaced them with a Piezo type, similar to its keypad, to be more durable and resistant for extended use.
Some of the updates include:
No moving parts (nowhere for chemicals to get into or under the button)
IP69K rating (old ones were only IP67)
316 stainless steel (more corrosion resistant)
Rated for 50,000,000 cycles (old buttons were rated for 1,000,000)
Same price (new button kit includes buttons, gasket, and Start/Stop labels)
The new buttons are compatible with all ALX-PRO V4 chemical allocation controllers, part number ALX-PRO-BUTTON-KIT.