TRS 1 (Tough Rubber Sheathing)
TRS 1 (Tough Rubber Sheathing) : A sheathing used on an insulated cable to form an outer protective covering of tough rubber composed of rubber mixed with hardening substances and suitably vulcanised to make it water-proof and resistant to decay, mechanical abrasion, acids, alkalis and other corrosive materials. PVC insulated and sheathed cable is now commonly employed for this purpose