Looks like a ceramic capacitor value of 220pf if it's 221. Make sure you get the proper voltage rating, usually you get double the voltage of what will go across it. If the PSU is designed to work for 100-240v then I'd get something at least double 240v rating or just go 1K volts if it fits if you can fit a higher voltage one, go for it. Usually with caps, the nearer the rating is to actual voltage, the shorter the life span of the cap. Last thing you want is a component working at it's max constantly.