Abstract: Apparatus adapted for attachment to transmission lines, the apparatus comprising a warning marker; and a warning marker application tool for applying the warning marker to transmission lines; wherein the warning marker comprises: at least one securing means adapted to engage the transmission lines; a first handle and a second handle each connected to the at least one securing means; a spring-biased clamp means adjacent the proximal end at the least one securing means; an attachment means adjacent the at least one securing means; and wherein the application tool comprises: a base means; a first protrusion and a second protrusion each protruding from a surface of the base means; a screw mechanism attached to the base means; wherein the first protrusion and the second protrusion are each adapted to releasably engage with the first handle and the second handle respectively, to position and clamp the warning marker to the transmission lines.