Check valves are always a good idea to have, however when it comes to reliability you get what you pay for. There are other good check valves on the market but we feel that the Georg Fischer Wye check valve is by far the most superior. They have a removable plunger that can be cleaned easily without having to remove the main body of the check valve from your plumbing. With the cost of some floors these days and other things an overflow can damage paying a few extra bucks for quality safety precautions can save a lot of money down the line.
Swiss-made check valves allow one directional water flow and are used to prevent back siphoning. Commonly used on return pump outputs to prevent water overflowing the sump in the event of a power outage, pump failure or maintenance.