CUSTOMIZATION OF SPACE - Designed specifically to allow customization of space for protein skimmer, media reactor, refugium and other equipment WATER LEVEL ADJUSTABLE - Adjust between 4.5" to 8" to meet your protein skimmer water height requirement NOISE REDUCTION - Comes with filter sock silencers to lower noise caused by water flow that goes into the filter socks Integrated filter sock holders that can hold 4" filter bags This kit fits in an Aqueon and Marineland 20 Gallon Long tank, glass tank not included