I purchased this item sometime ago but had not used it until recently. I opened and closed a bottle of Prosecco 4 times over a one week period and had it just as bubbly on the 4th occasion as on the first. I tried again on the 10th day and it had gone flat. I was only using a small amount each time to make an Aperol Spritz. Because I had reopened the bottle so many times, that still seemed good to me. I will test in the future to see how much longer it might last without so much opening. It is simple to use but my simple mind still got confused and it did not have any instructions whatsoever. So I looked at the video on the Amazon page and that was all I needed.Came with no instructions so I hope I'm using it correctly. The champagne did last a few days in the fridge.We like Bosca spumante, and have searched for years for a stopper to seal the bottle so that the contents could be enjoyed over a number of days. In our experience, Bosca spumante has a similar bottle-opening to most bottles of spumante, sparkling wine, and champagne; thus, a stopper labeled "champagne" could be used on most of the aforementioned bottles.We've been using the Winco Champagne Bottle Stopper for about 5 months, now, and it works wonderfully. The operation is simple and results in a nice, tight seal on the spumante bottle. When the bottle is re-opened, we consistently hear the hiss of gas being released, and the wine still bubbles and fizzes as it is poured. Typically, the bottle is resealed with the Winco 1 or 2 times over the course of a few days, and the wine is still bubbly and enjoyable. I've left a bottle refrigerated and sealed with the Winco for up to a week, and still heard the hiss when the Winco was removed (the spumante was bubbly, but not as much so as when it is enjoyed within a couple of days of opening). Some of the negative comments others have left regarding the Winco seemed to indicate that it may have a tendency to loosen and pop-off of the bottle. We have not experienced that, nor has our stopper's grips weakened. However, even if the grips did weaken, the stopper would work equally as well if one simply applied it to the bottle and then secured the arms with a rubberband or the like. In other words, the stopper would not be a complete loss even if it didn't work exactly as it was intended. The other two stoppers - Cilio and Metrokane Velvet - are virtually useless once they break, as there is no way to really salvage them and use them in an alternative manner.Cilio Champagne Sealer has also worked well for us. Its operation is simple, and it provides a decent seal with consistently decent results. However, if I leave the Cilio on a bottle of spumante for more than a couple of days, it does seem to leak a little. In other words, it provides a good seal for 1 or 2 days, but then the seal starts to weaken. Granted, sparkling wines weren't meant to be kept at length, anyway, but...our lives get busy. As with the Metrokane Velvet, once the Cilio breaks (or no longer functions satisfactorily), it will be a complete loss, as there doesn't appear to be any way to salvage it to use in a rudimentary way. We haven't had cause to replace it or discard it, since we primarily use the Winco stopper, so I can't really comment on its longevity. We've owned it for 5 months, and have used it 3 or 4 times.When they function properly, Metrokane Velvet Champagne and Wine Sealers form the tightest fit on the bottle and best preserve the gas/bubbles in the spumante. However, they are very fragile. We've owned numerous Metrokane Velvet stoppers, and no matter how gentle we were with them, they only lasted long enough to seal 5 or 6 bottles. Eventually, they just turn and turn, and the stopper no longer seals the bottle. I've read much helpful advice from other Metrokane owners who were able to repair their stoppers, but ours were always hopelessly irreparable.Works for most part at sealing, just a little tricky to engage and disengageIt's way to big for my regular bottles & I wish I could find a smaller size one for my regular bottles (for vodka or whiskey). I can't use this so I'm not happy.I've been into champagne cocktails lately, but only drink one cocktail per evening. This Cilio stopper has more than paid for itself. I just pop it on, and, voila, I still have bubbles the next day, with no loss of quality. After 3 days, the wine goes a little flat, but still has some effervescence. Overall, it has saved more money just in the wine I buy. The only reason I'm not giving it 5 stars is because it can sometimes get hung up on the lip of the bottle, depending on the brand. Fot those who are having trouble using it: Push the Cilio down on the mouth of the bottle till it's firmly seated. To open, press down on the button with the heel of your hand until you hear the ~~pfft~~ sound of the pressure being released, then use the thumb of your opposing hand to lift the stopper up. Once you get the hang of it, it's easy-peasy, Salut!Saw this in use at a local restaurant and decided to try it. Kept a bottle of champs bubbly for days!I purchased this as an add on gift to a champagne basket. Really nice, sturdy product.I bought as a replacement, as had a similar stopper for years. Initially I thought this was too small.struggled to get it on and of various prosecco bottles. Then found the technique. When putting on first depress the button, and place over the bottle, then release the top. When taking off reverse the process. Push and hold the button in, then lift off the whole cap. Not intuitive, but once I had the hang of it, it works well. Once I had got the hang of it, it works wellLoving this - you just push it down until it clicks into place. Then press the button to release!Easy!!There is a small rubber seal inside that when you click down, covers the top of the bottle and keeps the contents fresh and fizzy until you’re ready for a top up!It looks kinda cool too!It's the simple things?? a few people have had an issue getting it off. I don't know if I'm correct here but I found that when removing, pull it down over the bottle before you press the button. I think that releases the pressure slightly and then you just press the button and lift off. I did struggle like the gentleman that said he has to leave the bottle 10 mins and come back to it but, ain't nobody got time for that, so had a play around and pulling it down over the bottle before pressing the button seems to work. A bottle of Dom P was good for 3 days but I'd say no longer as the bubbles were starting to die off a bit. Happy quaffing?chin chingreat little gadget will keep fizz in a bottle for about 4 days so the first time you use it om half a bottle of champers it has paid for itself,i have also tried laying bottles on there side and no problems,you do need to twist the stopper after you push it down or it will not grip the bottleNot fit for purpose.I have used this type of product before with no problem.However, this went on the bottle but was then impossible to remove.I can’t return it because it’s still on the bottle and I can’t drink the remaining, (almost full) bottle the Prosecco because this is stuck on the top of the bottle. Furious!Finally managed to cut the top off (as well as my skin) using heavy duty cutters.