The Key parameter of the Add method initializes the Key property of the newly created timer. The MarkTimes collection can not contain two separate MarkTime objects with the same key, so the key should be unique. If you need to change the timer's key you can remove and add a new timer with a different key. The Remove method removes the specified timer. The Item property may be used to access the timer object based on its key. The MarkTimeFromPoint property indicates the timer from the cursor. Calling the Add method with the same key, changes the Time property of the timer.