Conductive plastic is NOT an insulator - these enclosures must be treated like a metal enclosure. Conductive plastic will act as a heating element - any significant current flow will cause the plastic to heat and produce smoke. IP54 Heavy Duty - EMI/RFI Shielded. Thick wall enclosure for EMI/RFI shielding applications using conductive plastic (a compound of ABS flame retardant plastic and stainless steel fibres) Designed for mounting PCB's Countersunk lid is secured with four M3x0.5-0.71 in. (18mm) long, Philips machine screws threaded into integral brass bushings, for repetitive assembley and disassembley Black matt textured finish