Inkqubo ye-3-layer esetyenziswe kwintambo yomthi okanye i-spacer cable, eyenziwe, ivavanywe kwaye iphawulwe ngokuhambelana ne-ICEA S-121-733, umgangatho we-Tree Wire kunye ne-Messenger Supported Spacer Cable.Le nkqubo ye-3-layer iquka i-conductor shield (i-Layer #1), ilandelwa yi-2-layer covering (i-2 kunye ne-#3).