The pneumatic nylon pipe and the protection pipe of the seven-core cable and the helix are made of PA11 (12) nylon pipe, with the merits of light weight, flexibility, corruption resistance, and weather fastness.

• 以PA11(12)尼龙管制作的气制动尼龙管及其为护管的七芯电缆，螺形线具有体轻、伸缩自如、耐腐蚀、耐气候的特点。