What a clever idea! This pump comes with a fine strainer cage to prevent solid particles entering the impellor and then blocking up the fountain heads. So far, so standard. But the fine strainer cage on this pump are arranged as \'wings\' on the side of the pump that can be detached. This means that if you want the pump to run a filter or waterfall you can detach the wings and allow solids (up to 4mm) to pass through the pump. This feature is important as it means that running as a solids-handling pump the pump strainer cage will not be prone to clogging up. This pump makes a great choice as a powerful fountain pump and as a back-up pump should your main filter pump break down for any reason. This pump is brought to the market by Oase under their Pontec brand. Oase are one of the premium aquatic brands and these pumps undergo the same strict quality criteria as their more expensive cousins.