HAWKUNG 10Pcs 3D Printer Filament Vacuum Compression Reusable Storage Bags with Manual Air Pump for Filament Storage, Compress and Remove Air to Prevent Humidity in Filament, 30x34cm

These vacuum bags are a must for 3D printers. If you want to have quality prints time after time you want to make sure that moisture does not get into your filament. These vacuum bags seal out moisture so that your filament rolls stay fresh without having to go through the long and annoying process of drying wet filament.Each bag more than comfortably holds a 1kg spool of filament and while it can be a little tricky to get started, they hold a seal very well. I put a bag of desiccant in the middle of the spool to help eliminate any moisture, then seal the bag. You definitely want to use rapid pumps to draw all the air out, and it may take a bit for the pump to get a good seal. However, with a little effort you will get a good seal that will keep moisture out of your filament. The bags compress down enough that your filament roll can fit back in a typical filament box, or you can clearly see the filament through the bags. All in all this is a great product that does exactly what it advertises.

It's difficult to figure out how to get the pump to work. Here's the trick...Put the valve flat on the table. With the pump, give it 5 or 6 slow, hard pulls. Then you will feel it pulling easier - that's when it starts sucking the air out of the bag.

As others have said, getting the pump to work right is a bit tricky. What works for me is to put the bag down on a hard flat surface like a countertop, press the pump down firmly, then tilt it slightly. You really don't need to press hard, just firm. The bags work great and are the right size for spools of filament.

These are tricky. When they work they work great. Sometimes I've had them leak only to find air back in them the next day. Also, the little vacuum can be tricky to line up and get to suck out the air. I'm sure much of this could be user error but still doesn't seem like it should be so difficult.

Came without pump. Will not work with shop vac. These are just expensive zipper bags. Unfortunately I did not open to use until too late to return so I am out $16.00. The so called Air Valve is just a printer circle on the bag!

The air vent does not allow any air through. I tried the hand pump along with multiple shop vacs, and no air gets through at all so they cannot be sealed.

These bags definitely do the job but it's tricky to get a 100% airtight seal on the zipper end. They include a plastic tool to help but even then it takes a few passes to get it to reliably seal shut.

Attaching the vacuum pump is persnickety at best. It can be done but it takes constant attention.

I saw some bad reviews of these and compared to my experience they are unfair.You do need to lay the part of the bag that you push the pump up against flat on a hard surface. That's not a bad thing, it's how they work.All of my reels fit inside, they come with a load of those gel bag things and you can suck nearly all of the air out of them easily.What more could you want from them?

When you use the pump it seems like it can't possibly work, but having read another review I persisted and it worked perfectly. So for half a dozen pumps it seems like you're wasting your time, then it suddenly kicks in and everything is fine.

Jus the right size for a standard 1Kg filament reel the vac seal can be a little temperamental to get going but once air vacuumed out it holds well. The pump is what you would expect and needs a flat surface to work from. Good value

Absolutely useless, the valve wouldn't allow air to be sucked from the bag. Fabric was too light causing the opposite side to seal against the valve.Returned for a refund.

When buying rolls of filament and not using it all in one go is wasting your money thease vacume bags are ideal and at the right price to keep your filament dry and in good condition it's like opening a new Bach of filament every time you use them