The Tristrip SOP convert geometry into triangle strips. Triangle strips are faster to render than regular triangles or quads.
Source Group - Specify a group of primitive to convert to tristrips. If no group is specified, then the entire geometry will be converted.
Constrain Strip Length - When checked on, the length (number of triangles) of the tristrips can be constrained to a maximum using the Maximum Strip Length parameter below.
Maximum Strip Length - Set the maximum number of triangles in each tristrip.