The 334 two star 11 piece full set precision double-ended angled and curved stainless steel probes are made of hardened stainless steel. The overall length is 5.5.Specs amp; FeaturesDouble EndedApplication: Kit includes 11 angled and curved probes., Quality: , Surface Resistivity : Conductive, Material: SS, OAL: 5.5 (137.5mm), Tip Width: .01 (.25mm)