Amazon.com: UCTRONICS Pi Rack Pro for Raspberry Pi 4B, 19" 1U Rack Mount, Support for 4 2.5" SSDs, Secure Shutdown, 0.96" Color Display for Raspberry Pi : Electronics
UCTRONICS U6143 Raspberry Pi 4 Rack Mount 19 Inch 1U Bracket w/ OLED
Raspberry Pi 19 inch 1U rackmount 5x RBPi Front Removable! - MyElectronics
Amazon.com: UCTRONICS 19” 1U Rack Mount for Raspberry Pi with SSD Mounting Brackets, Thumbscrews Front Removable Bracket Supports Up to 4 Raspberry Pi 5, 3B/3B+, 4B and 4 SSDs, Option SD Card