The VIS illuminator has 2 cord grips (a seal that tightens around a cable to provide a water-proof housing entry) on the back for connecting power and communication cables. In many applications, a communication cable may not be necessary, so one of these cord grips comes pre-installed with a water proof plug.  These cord-grips are design to accept cables with an outer jacket diameter of 2.9mm to 6.4mm (about 1/8” to 1/4”). If the cable you would like to use is smaller than 2.9mm (but larger than 1.6mm), NuOptic will provide smaller cord grips free of charge upon request. The cable jacket must be smooth and round to make a reliable water proof seal.  If used outdoors, the cable jacket material should be rated for outdoor use (contain UV stabilizers and be flexible over a wide temperature range).  Cabling intended for indoor use can degrade quickly in an outdoor environment.  The conductor gauge must be suitable for the illuminator model and for the length of the cable run.  As a general rule when using the NuOptic 36 VDC power supplies, we recommend using 18 AWG or larger conductors for 40W models up to 90m in length or for 80W models up to 45m in length. Please refer to the NuOptic power supply datasheets for more information. For convenience, NuOptic supplies a variety of high quality outdoor cabling for power, long run power, communications, and even power plus communications in a single cable. Contact a NuOptic sales associate for more information.