inTank Filter Floss Holder for JBJ Rimless Nano Cube 30 and 45 Fits JBJ Nano Cube Rimless 30 and 45 Aquariums Save money by not using expensive filter socks or two Media Baskets Desinged to be use with inexpensive filter floss, catching detritus and keeping rear chamabers clean Fits in either the left or right intake chamber, hangs on the baffle wall Made from high quality acrylic, soursed and built in the USA