Non-metallic construction with metal imbedded grounding grid|No need to install special wires and parts for grounding|Feed-through or dead-end grounded 1/2 or 3/4 in conduit openings for threaded conduit|Special grounding wire furnished with each box provided|Non-metallic enclosures with corrosion resistant parts coated with epoxy, PTFE or Mylar, these control stations offer unsurpassed resistance to chemicals|Silicone gasket, specially designed for the labyrinth-path point between cover and body, prevents entrance of moisture and dust|Smooth rounded integral bushing in each conduit opening protects conduct or insulation|Accurately tapped, tapered conduit openings for tight, rigid joints and ground continuity|Stainless steel pushbutton shaft operates within stainless steel bushing assuring long, maintenance free operation|Push button and selector switch contacts are silver cadmium oxide which are "sealed" in lower phenolic chamber isolated from corrosive elements|N1 Series is designed with unique Labyrinth-path construction to assure a flame-tight joint between body and cover|Explosionproof, with sealing fittings field installed adjacent to enclosure on all conduit runs, the N1 Series enclosures withstood a hydrostatic test|N1 Series has typical mechanical properties of 24500 psi tensile strength, 3% elongation at break, 33000 psi flexural strength and 1200000 psi flexural modulus|Electrical properties of sample specimens dielectric strength (in air) of 769 at 1/16 in|N1 Series is designed with high strength thermoplastic polyetherimide, together with thick walls (5/16 in) and sound structural design (rounded corners) provides superior resistance to impact and crushing|Non-factory sealed|120 VAC 6 W 6S6 Incandescent lamp