19" to 21" Rack Adapter
The 19-21 rack adapter is made to allow 19" trays and devices to mount into 21" racks, the adapters come as pairs with cage nuts and screws, and are available in 1RU and 3RU versions.
Part#
1RU: WC-1RUConversionBKT
3RU: WC-3RUConversionBKT