Input Shapes - connect a shape or shapes to create trails from.
Limit Length - when checked the trail(s) length will be limited to a maximum Length value.
Length - set the maximum length for the trail(s). Note - inactive when Limit Length is unchecked.
Start Frame - set the first frame for the Trail(s) to appear.
Path Type - select the curve type:
Beziers - Trails will be created as bezier curves.
Lines - Trails will be created as polygonal lines.