What are sock filters?

[reeferman06]

Hello all, I have see people talk about sock filters for awhile but I have never seen one, can someone show me pics please?

 

[scumonkey]

Try looking here for a photo of some socks...
http://www.filterbag.com/items/PONG100P4P.html

 

[reeferman06]

thanks

 

[AnAnemone]

One would place them in the sump to filter water at the drain lines from the tank. There are different types of them for different needs.
TimO