Pre twisted nro clamps yog siv los kho qhov nruab nrab thiab cov terminals ntawm overhead kab conductors. Lub nro clamp sib txawv nyob ntawm seb cov khoom ntawm cov hlau sib tw. Feem ntau, lub zog muaj zog aluminium alloy yog siv rau aluminium alloy hlau, thiab aluminium clad steel yog siv rau steel cored aluminium stranded nyob ntawm tej.
Lub hauv paus ntsiab lus ntawm nro hlau clamp: Ib txheej ntawm cov xaim ua ntej twisted yog ua ke los ua ib lub raj hollow. Thaum lub hollow raj qhwv ib ncig ntawm cov hlau thiab raug quab yuam, nws siv lub zog tuav ntawm cov hlau, kom ntseeg tau lub zog ntawm cov hlau. Lwm qhov kawg tuaj yeem kho rau lub insulator los ntawm ib lub nplhaib embedded.