Made of high quality 6061 aluminum material, black anodized. With set screws, there will be no damage to the aluminum rail Engineered horizontal mounting brackets are built to last and withstand the harsh conditions of the job site, ensuring maximum durability and reliability Easy to install, simply remove the aluminum rail from the Packout and install Slide the piece onto the guide rail, reinstall the guide rail, and then tighten the set screws when the mounting piece is in the desired position. The set includes: one upper and lower fixing bracket each, one matching set screw each, and 4 stainless steel adjustment locking hand-tightened bolts. JMSMSH Tool Box Level Mount Holder Set Of Two (Black)