A two-asset option that has a predetermined time window (monitoring period) during which one of two underlying assets is observed for barrier hits (breach), while the other is used to determine the payoff from the option. Monitoring takes place at some time over the option’s lifetime (the monitoring period is necessarily shorter than the option’s lifespan, and hence it is partial time- PT). The option is knocked in or out if the asset price being monitored hits or breaks through the barrier. If the barrier is hit or breached prior to the monitoring period, the hit (breach) doesn’t count and the option is said to be protected. The payoff from this option is dependent on the moneyness status of the second asset in relation to the option strike price.