Rust Proof Flush Cistern is a type of toilet cistern (the tank that holds the water for flushing the toilet) that is specifically designed to be resistant to rust and corrosion. The cistern is typically made from a rust-proof material such as plastic or stainless steel, which can withstand constant exposure to water and humidity without rusting or corroding. Overall, Rust Proof Flush Cistern is a convenient and efficient solution for households looking to conserve water and reduce their water bills.