Vivid Creative NOSOK Filter Sock Replacement - 4 Inch Leave Traditional Socks Behind with the NOSOK 4-Inch The Vivid Creative NOSOK Filter Sock Replacement - 4 Inch replaces a compatible 4-inch aquarium filter sock with a reusable and customizable mechanical filtration system. The NOSOK400 can use its heavy-duty nylon screen or inexpensive filter floss to provide filter sock-like performance without repeatedly washing dirty fabric socks. Screen or Floss Options for NOSOK400 Replaces compatible 4-inch aquarium filter socks Central filter core can be wrapped with disposable filter floss Heavy-duty nylon screen provides reusable 255-micron filtration Nylon screen drops directly into the NOSOK filter cage Screen unrolls flat for fast cleaning under running water Clogged filter floss can be discarded and quickly replaced Provides approximately 50 square inches of reusable screen filtration area NOSOK400 Dimensions and Filtration Capacity Product model: NOSOK400 Manufacturer SKU: NOSOK-400 Mounting diameter: 3.4875 to 4.25 inches with the included adapter Overall length: 6 inches from the mounting point Minimum filter-sock opening: 3.5 inches Nylon screen size when flat: 10.625 x 4.75 inches Approximate filtration surface: 50 square inches Screen mesh size: 255 microns Red Sea Reefer Compatibility for the 4-Inch NOSOK The NOSOK400 is designed for compatible 4-inch filter-sock holders with an opening at least 3.5 inches in diameter. Vivid Creative Aquatics also confirms compatibility with Red Sea Reefer filter-sock holders. Check the available space beneath the mounting point because the unit extends approximately 6 inches into the sump. Maintaining the NOSOK 4-Inch Confirm that the filter-sock opening is at least 3.5 inches in diameter and that the sump provides enough clearance for the 6-inch overall length. Install the appropriate mounting adapter in the compatible filter-sock holder. Drop the reusable nylon screen into the filter cage or wrap the central core with filter floss. Position the NOSOK where the aquarium's drain water will pass through the selected filtration material. Inspect the filtration material regularly to prevent excessive clogging and restricted water flow. Remove and rinse the reusable screen under running water or discard and replace dirty filter floss.