Enabled checkbox The small checkbox to the left of the plugin name is a checkbox that bypasses the effect when disabled. It also has a 'randomize' button that can be useful.
It opens a settings panel where you handle presets. Settings panel Whenever you have your mouse cursor over a snapin there is a small arrow at the top right corner (not visible in screenshot). VU Meter Displays the current output level on the left and right channels. Gain display Set how much to increase or decrease the volume, in decibels.