Intel NUC Rack Mount Kit "UM-INT-210" from racknex mounts three Intel NUCs with form factor Slim cleanly on 1.00U in a 19 inch rack.
NUC MiniPC 19 Inch 1u Rackmount Kit for 1-3 Nucs in Plastic for sale online
SL-2U-LLQ670E-GD
Intel NUC Rackmount Kit, 19 inch, 1.00U
1U NUC Server Shelf - Simply NUC
UCTRONICS NUC Rack Mount, 19 1U Rackmount Supports 3 Units of Low Model NUC : Electronics
NUC MiniPC 19inch 1U Rack Mount kit for 1x NUC - MyElectronics
Intel Nuc
1U Rackmount NUC, Dual NIC Option
Intel NUC Minipc 19inch 3U Rack to Mount 1-8 (Max. 12x) Intel NUC (8 Mounting Plates Included)
UCTRONICS NUC Rack Mount, 19 1U Rackmount Supports 3 Units of Low Model NUC : Electronics