2 core cloth & rubber (VIR) twisted mains flex with no outer sheath was once in common use. Most were dark red or brown. This flex has been obsolete for decades, and is rarely seen today. Occasionally its seen on historic electrical goods, and when found is usually in a dangerous condition. Apart from not meeting modern safety requirements it can be so fragile that when bent the old flex or cable it will perish and disintegrate in your hand exposing bare live wires. Despite once being in widespread use, it is rarely seen today because it deteriorates so badly over time.