Confused about 4 inch and 7 inch filter sock sizes

[NinnJinn]

The used 40 gallon sump I had sprung a leak I am not mechanically inclined enough to build another one so I am looking at purchasing a sump...

The sump I'm looking at says it takes 7 in filter socks does that mean the ring or opening of the filter sock is 7 in? Because currently the filter socks I use the ring is 4 in across

 

[xaflatoonx]

Yup. That’s correct.

 

[BigHildy53]

4'' versus 7'' is the diameter of the filter sock opening. Your 4'' filter socks won't fit a sump which is 7''.

 

[xaflatoonx]

Those are the two standard sizes sold.
4 inch and 7 inch rings.

The length varies.

 

[NinnJinn]

Thank you for the super fast response guys