Firstly, the wire gauge must be not less than 18AWG. The larger the wire diameter, the stronger the signal.
Secondly, the material of insulation must be HDPE. HDPE is tougher, chemically resistant, has a higher melting point, and has good low-temperature properties.
Thirdly, the thickness must be more than 30 mil. 45mil will be better.
Fourthly, the conductivity must be not less than 21%.