OMNIFilter 20" Heavy-duty whole house spun polypropylene cartridges are used for the reduction of sand, dirt, sediment and rust particles. Helps to protect your plumbing and appliances from getting plugged with sediment causing costly repairs. They are a cost effective solution for homes with sediment problems and can be used on chlorinated or non-chlorinated water supplies. These cartridges can be used in a number of OMNIFilter housings and also fit other major manufactures housings.