The installation of ONRAX overhead garage storage utilizes a 4.5″ steel mounting bracket that is secured with two 3″ lag bolts each. Each of these brackets has been pull tested to withstand up to 1250lbs! Some of our garage storage customers request longer ceiling brackets to accommodate specific placement of the overhead racks or to spread the load across more garage ceiling supports. ONRAX will gladly provide longer ceiling brackets when requested, at no additional coast, and they are included with all of our 72″ long units. The 4.5″ brackets provide more than enough strength for a standard installation, and are allow an easier and quicker installation than the longer brackets.