Came out of a retired server and these were used for swapping once a week backups. Excellent condition drive rack enclosure with internal tray AND an extra removable tray.  The aluminum cover is missing from the second tray but it is not needed and does not impair any functionality (the drive you install gets secured with regular HDD drive screws).

I believe that I have a key for the lock but it is not needed for proper function - it only locks the tray into the rack.  The HDD will power up as soon as the tray in inserted and closed with the lever.