Review on JR Products 571 VAC CHK Vacuum Breaker by Brian Young

I bought this valve, had it Exactly the same description as the valve I removed from my RV. However, after installing it, I found that it does not let water through in any direction, making it unusable. Then I discovered that there is a more expensive valve. I can't find any descriptions for them. Valves that let me know if mine is defective or if I need a more expensive valve. The seller must provide information in the description of both items so that the buyer can make the correct purchase.