I bought this to use with my Medela Pump and Go Advanced. These fit just like my Medela bottles so I can directly pump into them, at a fraction of the cost of Medela Bottles. I have also used these bottles for storing milk in the fridge and freezer without a problem. I have cleaned them by hand and in the top rack of the dishwasher with no problems. I have steam sterilized them with a Playtex microwave steamer, and in Medela QuickSteam Bags, again with no problems, including any dulling of the blue print.My only complaint is the two-piece bottle caps. I prefer the one-piece, and the two pieces tend to leak, so I wouldn't recommend using the included cover for transporting, although they seem to be okay for storing in the freezer. My solid Medela bottle caps fit on these bottles without leaking. I also have a bunch of Dr. Browns solid travel caps which fit great and do not leak.The rings are nice if you use them for feeding to baby using a nipple... I have used the standard Medela bottle nipple with these and it has worked fine.These are a great economical option for milk storage for pumping mothers. I paid about $1 per bottle when I purchased them, versus about $3-$4 for a medela bottle. I do a lot of pumping and I freeze/store my milk in the bottles, so it is convenient to have a lot of extra bottles available. I have been using these bottles for 5 months, and have several sets.I am a working mom and I have to store my milk in many different ways - from fridge to freezer. These bottles have been great because they are cheap (instead of using milk bags, I just freeze the milk in these bottles - a lot more convenient), reliable, and work well with my Medela pump.I've also used them as bottles and, while I prefer the VentAir Playtex, these did fine as bottles for feeding too.Here's what I like in particular:1. Good capacity (5oz) that is easily expanded (fits 6oz no problem)2. Reliable lids (I've taken the milk literally everywhere, including the plane, and have never had any leaks)3. Nice design (these are simple and classic, and I like that)4. Price (I've not been able to find a better deal)A couple of very minor cons:1. The blue print will peel off if you are sterilizing the bottles2. The lids can be used as lids or as nipple holders, which makes it a little less convenient when you simply want to close the bottle and do not use these as feeding bottlesThese work with the Medela Symphony and Pump In Style units that I am currently using. They are certainly a cheaper alternative than Medela 5 oz collection units. Even though it is noted in reviews and elsewhere, the issue with these bottles is that the caps are not a single, solid plastic piece. The caps function as a bottle collar and have a sealing disc that can be inserted in the collar's hole to keep milk inside. I don't trust sealing discs and they are so easy to lose down the sink drain. While I wash my bottle pieces in a little bucket rather than straight in the sink, the sealing discs are small and not brightly colored; this makes it is easy to just dump them out with the dirty bottle water. I bought a couple of packs of Great breastmilk storage for the price. I have breastfed all my children (3) and I use to use the storage bags but lost milk due to holes in them so I decided with middle one and now the baby to stick to using storage bottles so none of the milk it wasted. I read the reviews and one had stated that to 2 piece lid was a pain and I had a couple like that so when I found these I went ahead and ordered extra lids and am glad I did makes it easy to know milk is secure and won't leak or potentially get over exposed to freezer or freezer burn from the opening. Hard work to make,pump and save/store breastmilk and unlike knowing it will be ready for baby when he needs it :)I purchased these bottles for use with the Evenflo Double Electric Breastpump. I pack them with the lids on in a thin cloth bag that I place in my pump bag daily, then keep them in a cooler at work. Having extra bottles has been life saving when I do not have time to wash bottles right away or need to keep them in the fridge for several hours before transferring the milk to breastmilk pouches. I am giving it 4 stars instead of 5 because I sometimes have to wash them a couple of times in a row due to the plastic still feeling greasy after the first wash.These are some of my favorite bottles. I have a few different brands of bottles and these are by far the best made. They fit my Medela breast pump perfectly. I have not had any problems with warping or the print coming off when washing or sterilizing yet. The only downside for me is that fact that they can be used for feeding as well, so there is the extra part in the lid, which honestly isn't that big of deal. I don't store my milk in bottles, so I'm not sure how they hold up in the fridge or freezer. But overall I am very pleased with these bottles.I bought these to mix formula, but occasionally use them with my Medela pump. They are a much thicker and sturdier plastic than the Medela bottles. However I had planned to not use the two piece lid and to use my single piece Medela lids, and I find that because the threading on the neck is taller on these bottles than on the lids, the lids do not sit flat on the bottle mouth which causes leaks. I have not had any leaks with the two-piece lid that comes with these.I'm very pleased with these bottles. I've only been using them for a couple weeks so I can't comment on its durability, but the measurements on the bottle don't "seem" like they would come off easily like another reviewer experienced. The measurements stand out and are very easy to read (unlike the Medela bottles of the same size). The bottles are a good cute size and they work perfectly for my purpose - I pump into them with my Medela Pump in Style Advanced and then store them in the fridge. I also use the Dr. Brown's nipple directly on the bottles to feed my baby sometimes and they fit perfectly. The bottles wash easily in the dishwasher. The caps come in two pieces (silicone middle and plastic outer ring) which is useful with the Dr. Browns nipples as I just pop out the silicone centre and use the outer ring with the nips. If I weren't using them for feeding though, then the two pieces would be annoying to wash but not a huge deal. Overall, I like these bottles more than the Medela ones and they cost less than in store. Great value. I am very glad I got them.These storage bottles are very handy whether you use formula or breastfeed and need to store milk. The containers wash well and are easily marked for the amount you want to make. I store them in the fridge after I make formula and then they are ready to go whenever I need to grab one. They can be put into a bottle warmer directly if needed to as well.Ces 4 bouteilles supplémentaires sont indispensables pour celles qui veulent tirer leur lait.Permet de ne pas toujours laver les bouteilles après chaque séance de tire-lait et d’y entreposer le lait fraîchement tiré.Ces bouteilles sont exactement les mêmes que celles venant avec l’achat du tire-lait double de Evenflo. C’est ce que je recherchais.Bon rapport qualité/prix.Great quality and great price. I use it with Dr. Brown's narrow neck vent system, no leaks. Will definitely buy more. The only down side is the silicone seal: I think that over time with the steam sterilization it may damage like any other item made by silicone.I have the Evenflo pump, love the brand, the bottles are great. Great caps, can be used with standard nipple or with rubber stopper to store breast milk.