Radius Marker, Small, 22 in Circumference ORS NASCO Connecting and protecting electrical loads Connecting and protecting electrical loads is crucial to reliable Approved for use in aviation as well as automotive applications Applications include aviation and marine engines Precision tools made of rust proof aluminum and anodized for lasting protection The arms are precisely aligned with spring tension joints to guarantee accuracy and rigidity The holder accommodates flat or round soapstone and pencils All are a folding type design the three smaller models will fit conveniently into a shirt pocket All have sturdy friction joints to maintain rigidity and accuracy