Castrol Alpha ZN 220 has been discontinued in the UK. Alpha ZN 220 gear oil had mild extreme pressure and anti-wear properties and was intended for the lubrication of worm-wheel gearboxes and spur gears where a full extreme pressure gear oil was not required. Castrol Alpha SP 220 is the suggested replacement. It is a mineral gear oil of the same viscoisty but with full extreme pressure properties - CASTROL ALPHA SP 220
