Pitts Special question

[JDANDO]

I was out at KDSL this morning and this guy, N8PB, was doing a few take offs and landings.

http://jeremyd.smugmug.com/Airplanes/08Apr11-KDSL/1S7T0735a/1244628306_zoSJL-X2.jpg

Just wondering what the black and yellow "thing" off the wing strut/spar is?

[moose135]

That's used to help determine proper alignment relative to the horizon during aerobatic maneuvers.