OVV3D Filament Storage Bags 30pcs, Plus Size 32X34cm 3D Printer Filament Storage Bags Vacuum Sealed Kit with 30 Desiccants, Auto Pump,Perfect for 3D Filament Storage or Using After Filament Dryer Box

I've been using these for over a year. All but one of them has held the "vacuum", some of them for several months. They can be a bit of a pain to deflate because you have to press the pump onto the valve, i.e., there is no fitting, which tends to push one side against the other. Still, they work well and I'd buy them again.

I was looking for a way to store one off spools that don't get used often so they don't clutter up my humidity controlled storage box and this has worked out perfectly. Super easy to use. I was so happy with it that I bought another one as a gift for a family member.

I've had these for a while now and I'm disappointed.The air pump seems to work fine, and I was pleased at first. Put my filament in the bags, sucked out the air, and put them on the shelf. However, I'm finding that about 50% of the time when I go to get a filament off the shelf, it's no longer vacuum sealed as the bag has inflated and there's are inside.I'm not sure where the actual failure point is, as it appears the air is leaking in slowly. It could be the zipper, because it is very hard to close it. It doesn't seem to lineup quite right. I go back and forth over the zipper several times to make sure its sealed as best as I can. It could also be the air valve that is failing.Whatever the issue is, it's kind of a pointless product if it can't actually stay sealed.

I am fed up with buying bag kits with a pump, i dont need any more pumps!This kit supplies plenty of bags at a good unit cost without unnecessary items provided you have a pump or 10.Sure the bags dont last a lifetime but i dont expect them to, thats why i want 50 bags, because i have lots of filament and i take rolls in and out all the time.BTW - it seems that the latest batches of bags are now slightly smaller - not these - these ines are still the old size making it easy to get the rolls in.I will be buying more of these kits, hope the seller doesnt stop doing them!

THE BAGS:The bags seem well-made, and they hold a vacuum even after several uses, which is more than I can say for the SUNLU bags I bought. The problem is, they're barely large enough for typical FDM filament spools. You have to squeeze the widest part of the roll through the opening, which always feels like you're going to rip the bag at the seams. Once the spool's in place, there's not really enough room to get the vacuum pump flat on the bag so it will seal. It's a bit of a challenge getting the material just right. If the bag were 10% larger, it'd work a lot better.The kit also doesn't come with enough bag closing clips to go around, so you can't just leave clips on the bags; you'll have to move them from bag to bag as you open them. That's annoying.You can get just the bags, which is good. Some competing products, like the SUNLU, are only available as kits with a pump, which is wasteful.THE PUMP:I've bought this kit with both the manual and powered pumps.The manual pump is, frankly, a bad joke. It's too small, takes forever, takes too much effort, and feels like you're going to break it. There's nothing attaching the pump to the bag, so you have to hold it just so to maintain a seal, while pumping it. The pump moves a small amount of air, so you have to pump for 30 to 60 seconds to remove enough air. It's exhausting. The SUNLU pump (which isn't compatible with these bags) evacuates their bags with 3-4 strokes, because it's a lot larger.The automatic pump works, eventually. It takes as long as doing it with the manual pump, but without the effort. The thing is, the pump gives off an overheated-motor smell that makes me wonder how long it'll last. It charges via Micro-USB; a cord is included but not a charger. It gives no indication of battery percentage, nor does it give any indication that it's done charging. (I wonder if it just keeps charging the battery, which would be bad for battery life.)THE DESSICANT:It's silica gel, which works better than clay-based. But it's not reusable and has no indicator function. It'll work, but you're better off substituting indicator-based, reusable silica-gel packets.

I’ve used over 100 of these bags and counting and I keep coming back for more. I use the clip to ensure the bag is closed, a battery-powered pump to suck out the air, and I rub my finger over the vacuum port to ensure it’s sealed. Since I’ve started buying these they increased the size of the bag slightly so inserting the spool into the bag is easier.Occasionally a bag doesn’t hold a seal after multiple open/close cycles. When that happens I open and re-seal the bag and try again. If the bag still won’t hold a seal I throw it away. This doesn’t happen very often.At least one of my printers is printing day or night and keeping the filament dry helps ensure the best prints. I’m completely happy with the performance of these bags and as you can see from my pictures I have a bit of experience with them. 😆

edit: Ordered a very similar item from another brand. that one I can use the vacuum on both brands, so I did get the bags to work. it seems to be the vacuum itself that isn't sealing right. But am keeping it for the bags. two days so far the bags are holding their seal. Modded review to 3 stars. I can get the vacuum pump to seal and stick to my hands, the desk, and even vertical drawers on my desk. Seals to practically anything-but the bags! Ive tried 4 bags so far now, not a single one will pump air out. Ive tried even putting my hand in the bag and over the valve area but that's the one time it *won't* stick to my palm! Ive tried empty bags on flat surfaces, with a spool inside, without a spool, everything I can think of, made sure to use the seal zipper things, but can't even get the air to come out at all unless Im just squeezing the bag. So for now, totally useless.