Arlington FS50-1 Zinc-Die cast Weatherproof Electrical Box Holder, 1/2-Inch, 1-Pack. Zinc-die cast construction suitable for outside use. Simple to install - just screw the box support into electrical box and secure with 1/2-Inch conduit or pipe. Commonly used for suspending electrical boxes and fire alarms (smoke detectors) between joists. UL and CSA Listed, Made in USA. Inner diameter hole for conduit or pipe measures .860-Inch. In the event any of our products are found to be defective, we will replace them with new product free of charge. The time limit for this warranty is one year following the date of sale or one year after the date of installation, whichever is the earlier date. This warranty does not apply when the product is used for any purpose other than the intended use as described in the Arlington literature. This warranty does not apply when the product is used for any installation which would violate the national electrical code or any code which takes precedence in a particular jurisdiction. Labor is not included.