Mobile Equipment JANX has over 160 mobile nondestructive testing units consisting of 4-wheel drive, 3/4 ton and one ton trucks. Each is equipped with its own power plant, and a portable, heated & air-conditioned darkroom, that contains developing tanks, film dryers, and film viewing equipment. For the larger projects, we offer portable darkroom trailers, ranging from 18 to 25 feet long and fully equipped, 44 foot long mobile office/darkroom combinations.