Check the listing for details. TETRA Whisper 20i In Tank Aquarium Filter. Condition: New. Listed at 25.99 USD. TETRA Whisper 20i Filter AUCTION is for ( 1 ) : TETRA Whisper 20i In-Tank Filter 125 GPH for up to 20 GALLON TANKS Whisper® Internal Power filters are the ultimate in quiet, convenient 3-stage filtration. The dualsided mesh of the Bio-Bag® catches debris and fish waste while the activated carbon absorbs odors and discoloration. Biological filtration is provided by the Bio-Scrubber. Bio-Scrubber's anti-clog design provides complete biological filtration with the convenience of less maintenance. Because the Bio-Scrubber has a solid back, water is forced to flow evenly over the bacteria-rich bristles. * Space-saving, powerful in-tank filters * 3-stage filtration performance and quiet operation * Mounts easily and discreetly inside your aquarium Tetra Space-saving design enables the same quality and performance as external filters without the noise. Whisper In-Tank Filters offer 3-stage filtration performance and quiet operation. Mount discreetly inside your aquarium for clean, clear water and the added convenience of placing your aquarium flush against a wall. Adjusts easily to high or low water levels (as low as 2") with mounting suction cups and/or bracket. Includes one pre-assembled Whisper Bio-Bag filter cartridge. Please contact me for international shipping rates or with any questions or concern that you may have about my products. Thanks for looking !