Does this fit in Eshoppss Rs-75 3rd generation?

We have not used the Eshopps 3rd Generation RS-75 Reef Sump. According to Eshopps their socks are 200 Micron with a 4" diameter ring x 13 inches long. Our filter socks have a 4 inch ring but are 14 Inch long. The advantage of using our socks is they are thicker and have heavy duty stitching making them more durable - and they are even washable. Since our socks are flexible you should be able to fold the extra inch over in the bottom of your sump. We do offer these same filter socks in a 2 pack.