. The ADJSHELFHDV 1U Adjustable Heavy Duty Vented Rack Mount Shelf lets you add a high-capacity adjustable 1U shelf to virtually any standard 19-inch server rack or cabinet.This heavy duty rackmount shelf can be adjusted from 19.5in to 38in (mounting depth) to fit your rack while the vented design improves air flow and help to lower temperatures in the rack. Constructed using 1.2mm SPCC commercial grade cold-rolled steel providing the ability to hold up to 113kg (250lbs) of equipment - a durable solution for storing large non-rackmount pieces of equipment heavy tools or peripherals in your rack or cabinet..