Rackstuds Smart Rack Mounting System, 2.7mm Version, 100-pack A universal replacement for cage nuts* Inserts from the front so no more fiddling behind the rack Rackstuds provide a place to support your gear Rackstuds are much simpler, faster, safer and very strong Suitable for rails between 2.2mm/0.086" and 2.7mm/0.106". Use RSL100 if rails are &lt;2.2mm/0.086"