Watering cans with mesh filters

Mesh filter

— a small filter mesh, integrated into the neck or inserted into the spout of a funnel, acts as a simple pre-filter when transferring gasoline, diesel, or other fuel. This funnel is especially useful for machinery sensitive to contamination: even a small speck can cause inconsistent engine performance, so the filter mesh "provides protection" from accidental debris that might have entered the canister or settled at the bottom. Unlike a regular spout without a filter, there is less chance of problems after refueling, but it's important not to confuse it with a full-fledged fine fuel filter in the system — the mesh specifically screens out large and medium particles, rather than "completely cleaning the fuel."