Stainless steel mesh filter guards with beautiful and solid design - Definitely Safe and Prevent baby shrimps/fish from sucking in the filter...come with 7 sizes in diameter. Please measure your filter intake diameter to make sure on the size:
9mm - Fit Zoomed 501, Boyu...and any filter intake with size 9mm
13mm - Fit eheim 2213-2215-2232, zoo med 511...and any filter intake with size 13mm
16mm - Fit any filter intake with size 16mm
17mm - Fit eheim 2217, Aquaclear 20-30-50, Rena XP1-2-3...and any filter intake with size 17mm
20mm - Fit any filter intake with size 21mm
24mm - Fit any filter intake with size 24mm
26mm - Fit Fluval C4..and any filter intake with size 26mm
Anthony (Submitted on Mar 1st 2017)
I needed a prefilter for an Aquaclear 50 that kept clogging in just a few days. I tried a prefilter sponge, but it itself rapidly clogged. A friend recommended I try this mesh filter. I'm glad I did: I've had it on for two weeks, and the filter has yet to slow down, let alone clog. I'm very impressed!
Luke (Submitted on Feb 28th 2017)
Fits well with my ZOo Med 10 canister filter. 9mm.
TVW (Submitted on Jul 18th 2016)
I tried a much more expensive pre-filter from a large online retailer only to find that the holes were large enough for newborn shrimp to squeeze there way through.
Purchased this pre-filter and it is a far better solution. The mesh holes are tiny enough that not even newborn cherry shrimps can fit through, even if they try. That said, I've been running my ZooMed 501 for some time in my planted tank and have not had any issues with it clogging.
The pre-filter is very sturdy and you don't feel like you are going to dent it when putting it on. Speaking of installing it, the fit was perfect.
The only downside of this product is that the rubber material covering the ends has some faint white writing on it which some people might find unappealing. I just made sure it was facing toward the back and haven't seen it again.