The PJ664 is the smallest size in the PJ Series of Type 4X polyester junction boxes, measuring 6.10 in H x 6.10 in W x 4.13 in D (155 x 155 x 105 mm). This version has a lift-off cover held by screws, and it is designed for use as an instrument enclosure, electric, hydraulic or pneumatic control housing, electrical junction box or terminal wiring enclosure where equipment may be hosed down or be very wet.

Both box and cover are compression molded fiberglass reinforced polyester with a gray finish, and the material is easily punched, cut or drilled. Enhanced UV inhibitors protect against outdoor weathering. The cover is fastened by four stainless steel captive cover screws with retaining O-rings, threaded into #10-32 brass inserts, and a captive, oil resistant closed cell neoprene gasket provides a positive seal.

Four stainless steel mounting feet attach to brass inserts at the rear of the enclosure, giving an overall height of 7.95 in (201.93 mm) on the drawing. Inside, #10-32 threaded brass inserts accept the optional 14R0505 inner panel (4.88 x 4.88 in, 124 x 124 mm) or a terminal kit, with mounting hardware included. Shipping weight is 3 lbs (1.36 kg).

Lift-off cover PJ664 carries the series ratings of UL 508A and cUL Type 1, 2, 3, 4, 4X, 12 and 13, plus Type 6P and IP68 in addition to IEC 60529 IP66. It is rated for operating temperatures from 130°C to -40°C (266°F to -40°F) and is RoHS and REACH compliant. A hinged cover version is available as PJ664H.