The PJ664L is the smallest snap latch model in the PJ Type 4X polyester junction box series with continuous hinge door, measuring 6.10 x 6.10 x 4.18 in (155 x 155 x 106 mm). It is designed for instrument enclosures, electric, hydraulic or pneumatic control housings, electrical junction boxes and terminal wiring enclosures, and provides insulation and protection where equipment may be hosed down, very wet, hot or exposed to highly corrosive conditions.

Box and cover are compression molded fiberglass reinforced polyester in gray with enhanced UV inhibitors, and are easily punched, cut or drilled. The door is supported on a continuous stainless steel hinge and closed by a single stainless steel lockable snap latch located on center; the series describes these as draw type fasteners with a provision for padlocking. The PJ664L drawing shows a closed cell neoprene gasket.

Four 10-32 threaded brass inserts with plated carbon steel screws take the optional 14R0505 inner panel, 4.88 x 4.88 in (124 x 124 mm), or a terminal kit; back panels are shown in 0.100 in aluminum, 0.075 in white steel and galvannealed, and 0.125 in fiberglass.

Four stainless steel mounting feet attach to rear brass inserts with stainless screws, for 7.95 in (201.93 mm) over the feet with 0.34 in (8.74 mm) holes. It is UL 508A and cUL (CSA 22.2 No. 94) Type 1, 2, 3, 4, 4X, 12 and 13, complies with IEC 60529 IP66, operates from 130°C to -40°C (266°F to -40°F) and has a 6.78 J (5 ft/lb) impact index. Shipping weight is 3 lbs (1.36 kg); REACH and RoHS compliant.