100 Count Syringe Filter, Nylon Hydrofilic Membrane 25mm Diameter 0.22um Pore Size, Syringe Lab Filters, Non Sterile Filtration (Green)

Edit: these do not have a pre-filter as advertised though the most important part if the 0.22um size filter. So if you are making single use poppy preperations for inj, it's such a small amount (a few ml) and these 25mm diameter filters will work fine. Though I prepare enough for several days (stored in 20ml brown tint sterile vials bought on Amazon also) so I now use the 0.22um pore filter x 33mm diameter size by locofiltr which I have confirmed do have a pre-filter (which is very helpful for the amount I prepare at one time). These are still very good for single use filtering so I will give them 3 stars & will leave my fact based research info below on how filters work with home inj preps.- These filters are excellent for filtering home inj mixtures and solutions via a syringe attachment. I NEVER prepare a solution without these anymore, & have never had an issue since. A little money now saves misery later.- Studies have shown (can search online) these filters filter out 100% of endospore forming bacteria that are common and can cause infections and abscess. These 0.22μm filters are the size that should be used. The Endospore bacteria are found to be no smaller than 0.8μm so these filter them 100%. Also the PES is found to not filter any of the "active compound" itself. The loss that can occur is from a drop or two that may remain in the filter unit. NEVER force air through to produce those remaining drops, it can compromise the filter integrity (these filters are meant for fluid, not gas (air)). A burst of a few foamy drops after forcing air through can mean the filter has been torn/dislodged and residual particulate and filtrate have been forced through or around the filter (the stuff you're trying to filter out & should be refiltered through a new filter). Instead of pushing air at the end pass a small amount of water slowly through after to get those last couple drops out.- Less fluid remains behind with the smaller 15mm or 13mm diameter filters than with the 25mm (that's the diameter size of the entire unit, not the micro-pore size of the filter material inside which should ALWAYS be 0.22μm) I caution against ever using 15mm or 13mm diameter filters as they will clog very quickly and they have far less surface area to filter those abscess causing bacteria. (the 25mm filters are rated for 10ml to 100ml total fluid filtered. Whereas the 13mm are rated only for 0ml to 10ml. Definitely a better value with the 25mm diameter filters). I don't myself reuse or suggest reusing a filter though as long as there isn't much resistance on repeated uses. Regardless of how much fluid you have passed through a filter, once you feel resistance don't force!! It's time to use a new one. --- A last note, NEVER use PTFE filters for your inj poppy fluid preparations in syringe. PTFE are hydrophobic (hate fluid) and best used for gas exchange filtration. And the Nylon can tend to bind protein and amino acids which can result in filtering a bit of your "active compound". Use the PES filters only for home inj preperations.(poppy).

Would and have purchased again

The filtration diameter is 19 - 20mm, not 25.Unidirectional filtration - the flow is only from the short luer-lock to the longer, narrower output.

They work fine but just be aware when ordering that the PES filters are actually MCE. Check back often because they often have great prices.

Thought these were okay at first, before I had a comparison with a filter that *actually* had a prefilter in it. Unlike what it says in this item's description, these do not have a GF (glass fiber) prefilter. I contacted the seller: apparently *none* of LabZhang syringe filters come with a GF prefilter. I'm assuming they got away with it for so long because the plastic housing around the membrane is welded shut & practically impossible to separate. It takes a Dremel tool or something similar to get these open; which is how I confirmed that they only have a single membrane.Have contacted both the seller and Amazon about this fraud/false-advertising multiple times. They both said they would remedy this, but they haven't, which is why I'm taking the time to write this! (Amazon has so far only been willing to refund a small portion of the money spent on 5+ orders)If you want an affordable solution for PES membrane-only filters, these work alright. One other issue is that the containers holding the filters are weak; and Amazon ships them in a flimsy envelope. That combo makes it so they are apt to burst open and spill all over the envelope; making cardboard filaments, other debris, etc get into the outlet of the filters, completely defeating their purpose.

These filters seemed like a great option, however, the luer lock fitting did not mate well with all of the syringes in our inventory. Leaks were common except when using some of the lowest quality syringes

The filters hardly fit and my hand hurts screwing them together, and they still don't work. only about half the products goes through and the filter stays full from the rest which you cannot coax out. In the end I had to buy the better ones!

Your description is contradictory.