Thanks andrew,
I have another queston about this next part of the instructions:

7. Remove the stab from your building board. Inspect all
the glue joints and add CA to any joints that don't look
strong. Cut the ends of the leading and trailing edges so
they extend past the end of the stab by about 1/16". Use
your bar sander to finish the job by sanding the ends of the
LE's and TE so they are flush with the end of the stab. Cut
the 1/8" x 1/4" tips, then glue them to the end of the stab.

The last sentence talks about the 1/8" x 1/4" tips..... what are those???