Rust Veto 4221 and 4221T are both emulsified water-based products. The cleaning effect of RV 4221T is better (small and medium parts), while the anti-rust effect of RV 4221 is slightly better (medium and large parts). After the moisture dries, a thin oil film is formed to protect the workpiece. This type is easier to clean and degrease in the follow-up. Indoor protection can last for at least three months.