I believe the most of users know the Double Top Pattern, so I omit the introduction.
The algorithm uses 10 internal watchers to identify the incomplete M-pattern. If any of the watchers finds the pattern, the signal will be plotted on the chart. You can customize the lookback periods for the watchers as well as you can specify the precision of the difference between two possible tops.
By default, all watchers wait for bar closing to avoid repainting issues. You can switch off this option.
Additionally, you can shift up/down the signal labels to the preferred distance.