Thanks for the question - it's made from 316 stainless steel, so unless you accidentally throw it away or abuse or break it I'd be surprised if it doesn't last for many thousands of shots.  We've been using the same screen daily for the last few months - probably a few hundred shots at least - and it's identical to a brand new one, so in theory these things will last indefinitely.  

Stainless steel filters are on the surface very similar to Aeropress steek filters. However, they have a smaller diameter and are designed to fit your basket. They offer a couple of advantages over mesh filters: mm Mokapot filters work well for regular-sized portafilters, while Aeropress filters aren’t the ideal size, even though they are commonly recommended. It’s useful to have them both IMO, but this doesn’t necessarily mean you need to break the bank and buy the most expensive ones. Go ahead and read about how to clean an espresso filter basket easily. Coffee grounds Baskets

Advanced Techniques in Puck Preparation

Mesh filters are the original choice. They are easy to buy online and can be found in various sizes and densities. You can use paper instead of a screen. Use scissors to cut baking paper in the shape of the coffee basket and once you’re done with tamping you can put it above the coffee grounds. The espresso filter distributes the water more evenly across the bottom of the filter basket, which allows the espresso to flow through every basket hole for a faster flow rate.

Best of all, paper filters can be thrown away with your ground coffee, so they don’t add any maintenance. Adding a paper filter underneath the coffee grounds is an easy way to make brighter, sweeter shots. That brighter flavor may work against you if you prefer richer, more full-bodied shots or like making milk-heavy drinks like lattes. A good way to detect any issues with your coffee extraction and whether it’s channelling or not is to use a naked portafilter.The pre-infusion will mostly solve this problem by dumping a small amount of water at a low pressure on the coffee bed, before the extraction. However, the water will still pour in streams from the shower head, and there are still a lot of chances to get channeling. With a relatively low price point compared to so many things in the jungle that is espresso accessories, it’s a small investment that can make a big difference in your workflow and shot consistency.