Astrix instead of password characters

Someone a while back asked if it is possible to hide the characters for a textbox like they do for passwords in most websites. The answer that was given no that it is not possible. Then I came across this example that does just that. I removed all the vba code, except the show userform code, and all other objects so obviously it's a property of the textbox but I can't seem to isolate it. Does anyone know which property it is?

abousetta