1. Cov cores loj, tag nrho cov dej qhuav thaiv cov qauv, tsis muaj cov tshuaj pleev xim, ntxuav thiab ceev ceev thaum tsim kho, thiab tsis muaj kev cuam tshuam rau ib puag ncig.
2. High modulus iav fiber reinforced yas qws (FRP) central reinforcement.
3. Longitudinally qhwv ob-sided zaj duab xis npog corrugated steel daim kab xev armor tuaj yeem txhim kho lub siab sab nraud ntawm optical cable.