Used in a system that checks cheese bags for leaks under vacuum. Typical solenoid valves don't work on vacuum applications, but this does just fine. I used it to bleed off the vacuum after the test is complete, as part of an automated system. Will buy several more for a bulk build of the test system to go out company-wide.

It works fine for now just wish it had the manuel open incase of anuthing!!

I received conflicting responses for my question on how the auto-return models work. I hope that the super-cap is the correct response since that is how I would designed it. But I went with the three wire setup to save money.
Corrosion on the leads indicated my unit was in storage for a long time but after trimming and re-stripping the leads it tested fine with a 9V battery and after installation it worked as expected with a small 12 v wall wart and asymmetric timer relay.
I used it for an automatic aquarium water changer system after finding that algae quickly clogged the diaphragm of a cheaper valve such that it would not fully close. But I suspect that algae will be no match for the high torque stainless steel ball. If your water is dirty, then this is your best solution.

Close time is ~3.5s at 13.8v, 7 sec at 7v, 5 sec at 9v, and 3.5 or so seconds above 10v (only tested to 15v).

I run PWM on the yellow common to slow it down for a 10 second close time using the microcontroller running the system with two of these valves in it. Prevents sudden pressure spikes from damaging RO (Reverse Osmosis) membrane and other filters. Also using it on the auto-flush of membrane for same reason, no sudden shocks/water hammer on sensitive materials and an overall plastic system.

The 3 wire is the one you want if using a microcontroller or PLC to operate, though you'll need to modulate the ground to slow it down to match the 10psi/sec rate of change spec of Membrane manufacturer. This is going WAY above and beyond, nearly all commercial systems use the cheaper solenoid valve, but that shock isn't good for the thin film membranes. Now running within spec to see if membrane lives more than 6 months. If there's no update, it worked. Has been working great for a month now.

Current wiring: SPDT Relay with 12V Common, NO -> Blue and NC -> Red for a normally open. Yellow goes through a MOSFET modulated via PWM to control speed of opening and closing in software via pressure sensor and flow meter feedback. Home systems likely don't need this level of specification, but if you're bored and want a project, I've made the code open source. Currently writing a port of it for Arduino so there's a plug and play system where no programming/electronics/systems knowledge is needed.

Best thing about it is freeing up another Solenoid valve to flush the first 90 seconds of RO water directly to waste instead of through DI Resin, the savings in Resin life extension by 100x alone will pay for these valves in a year.

Fast shipping, good quality & price along with good instructions