Bests & Worsts Reviews from Amazon

We purchased the metal K cup to replace the factory plastic one and liked the idea of the design and looks of the longevity the unit would provide. Unfortunately the lid will not stay closed during use and consistently adds coffee grounds into the cup. It's not just a few grounds but quite a bit making for a chewy ending to the cup of coffee. We tried placing the cup in different positions and rolled the o ring down on the needle as suggested by the seller but haven't had any success. The only way to get the cup to function close to advertised is affixing a rubber band around the cup to hold the lid down.