Sufficient Quantity for Replacing: the package comes with 16 pieces of aquarium socks in white, enough to satisfy your using and replacing demands in Reliable Workmanship for Lasting Service: made of quality polypropylene, the 4 inch filter sock is tightly sewed, pliable and serviceable, which can be applied and washed for many times Appropriate Size for Most Sock Holders: designed with a size of , the aquarium filter sock is equipped with a plastic ring (. 4 inches in diameter), compatible with water tanks Satisfactory Working Performance: the sump filter sock can do well in filtering the debris, sand and sludge in your tank, to reduce the abrasion of your tank, thus prolong its service life To Create a Better Water Environment: characterized by interlocking micro-felt fibers, the sump socks can catch food residues, fish waste, decaying plants, dust and other floating particles, which can improve the water quality in the tank Color: White Material: Polyester Package Contents: 16 x aquarium filter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.