Hey pumping moms! If you're using Freemie closed system collection cups and dealing with decreased suction or milk backing up in your tubing, it might be time to replace those valves. These Maymom replacement valves are exactly what you need to get your pumping sessions back to optimal performance. First things first - these ONLY work with Freemie closed system cups, NOT the open system version. If you try to use them with open system cups, they just won't fit properly on the valve base. The package comes with four white duckbill valves made from 100% BPA-free silicone that's safe and durable. Here's how you know you need new valves - if they're looking wide open when relaxed instead of staying closed, or if you notice any tearing or damage, that's definitely affecting your suction power and milk flow. With regular use, valves typically last about two months before they start wearing out, so having replacements on hand is super smart. Maymom offers a solid 3-month replacement warranty on these valves, which is pretty generous compared to some other brands. Quick heads up - sometimes Freemie valve bases can vary slightly between batches, and if these don't fit your particular base, the seller will help you out with a refund. It's important to know that Maymom is an independent company and not affiliated with Dao Health (the Freemie makers), but they've designed these specifically as compatible replacements. Keeping fresh valves in your pumping system makes such a difference in performance and efficiency. Definitely worth having a few sets on hand so you're never stuck with poor suction during those important pumping sessions!