It should be the first consideration before buying a perfect shower filter for you. Most shower filters are made of plastic or metal. If you want low cost and easy-to-maintain filters, you can use a unit made of plastic. However, after regular use, these types of filters can cause some problems like leaking or cracking. On the other hand, metal units are a little more expensive but more durable. You will find some rust-proof metal water filters on the market, but you have to pay more for these items.